diff --git a/dataset/lm_dataset.py b/dataset/lm_dataset.py
index 1dd1558..cf663d4 100644
--- a/dataset/lm_dataset.py
+++ b/dataset/lm_dataset.py
@@ -1,9 +1,33 @@
 from torch.utils.data import Dataset
 import torch
 import os
+import random
 from datasets import load_dataset
 os.environ["TOKENIZERS_PARALLELISM"] = "false"
 
+def pre_processing_chat(conversations, add_system_ratio=0.2):
+    SYSTEM_PROMPTS = [
+        "你是一个知识丰富的AI，尽力为用户提供准确的信息。",
+        "你是minimind，一个小巧但有用的语言模型。",
+        "你是一个专业的AI助手，请提供有价值的回答。",
+        "你是minimind，请尽力帮助用户解决问题。",
+        "你是一个可靠的AI，请给出准确的回答。",
+        "You are a helpful AI assistant.",
+        "You are minimind, a lightweight intelligent assistant.",
+        "You are a friendly chatbot. Please answer the user's questions carefully.",
+        "You are a knowledgeable AI. Try your best to provide accurate information.",
+        "You are minimind, a small but useful language model."
+    ]
+    if conversations and conversations[0].get('role') != 'system':
+        if random.random() < add_system_ratio:
+            return [{'role': 'system', 'content': random.choice(SYSTEM_PROMPTS)}] + conversations
+    return conversations
+
+def post_processing_chat(prompt_content, empty_think_ratio=0.1):
+    if '<think>\n\n</think>\n\n' in prompt_content and random.random() > empty_think_ratio:
+        prompt_content = prompt_content.replace('<think>\n\n</think>\n\n', '')
+    return prompt_content
+
 class PretrainDataset(Dataset):
     def __init__(self, data_path, tokenizer, max_length=512):
         super().__init__()
@@ -37,9 +61,9 @@ class SFTDataset(Dataset):
     def __len__(self):
         return len(self.samples)
 
-    def create_chat_prompt(self, cs):
-        messages = cs.copy()
-        tools = cs[0]["functions"] if (cs and cs[0]["role"] == "system" and cs[0].get("functions")) else None
+    def create_chat_prompt(self, conversations):
+        messages = conversations.copy()
+        tools = conversations[0]["functions"] if (conversations and conversations[0]["role"] == "system" and conversations[0].get("functions")) else None
         return self.tokenizer.apply_chat_template(
             messages,
             tokenize=False,
@@ -67,7 +91,9 @@ class SFTDataset(Dataset):
 
     def __getitem__(self, index):
         sample = self.samples[index]
-        prompt = self.create_chat_prompt(sample['conversations'])
+        conversations = pre_processing_chat(sample['conversations'])
+        prompt = self.create_chat_prompt(conversations)
+        prompt = post_processing_chat(prompt)
         input_ids = self.tokenizer(prompt).input_ids[:self.max_length]
         input_ids += [self.tokenizer.pad_token_id] * (self.max_length - len(input_ids))
         labels = self.generate_labels(input_ids)
@@ -87,22 +113,24 @@ class DPODataset(Dataset):
         self.padding = tokenizer.pad_token_id if tokenizer.pad_token_id is not None else 0
         self.bos_id = tokenizer(f'{tokenizer.bos_token}assistant\n', add_special_tokens=False).input_ids
         self.eos_id = tokenizer(f'{tokenizer.eos_token}\n', add_special_tokens=False).input_ids
-        self.data = load_dataset('json', data_files=file_path, split='train')
+        self.samples = load_dataset('json', data_files=file_path, split='train')
 
     def __len__(self):
-        return len(self.data)
+        return len(self.samples)
 
     def __getitem__(self, index):
-        item = self.data[index]
-        chosen = item['chosen']  # 是一个 list，里面包含若干 {role, content}
-        rejected = item['rejected']  # 同上
+        sample = self.samples[index]
+        chosen = sample['chosen']  # 是一个 list，里面包含若干 {role, content}
+        rejected = sample['rejected']  # 同上
         chosen_prompt = self.tokenizer.apply_chat_template(
             chosen, tokenize=False, add_generation_prompt=False
         )
+        chosen_prompt = post_processing_chat(chosen_prompt)
 
         rejected_prompt = self.tokenizer.apply_chat_template(
             rejected, tokenize=False, add_generation_prompt=False
         )
+        rejected_prompt = post_processing_chat(rejected_prompt)
         chosen_encoding = self.tokenizer(
             chosen_prompt, truncation=True, max_length=self.max_length, padding='max_length'
         )
@@ -169,11 +197,13 @@ class RLAIFDataset(Dataset):
             role = 'user' if i % 2 == 0 else 'assistant'
             messages.append({"role": role, "content": turn['content']})
             answer = turn['content']
-        return self.tokenizer.apply_chat_template(
+        prompt = self.tokenizer.apply_chat_template(
             messages[:-1],
             tokenize=False,
             add_generation_prompt=True  # 这里需要True
-        ), answer
+        )
+        prompt = post_processing_chat(prompt)
+        return prompt, answer
 
     def __getitem__(self, index):
         sample = self.samples[index]