OpenMed-PII-Chinese-ModernMed-Large-395M-v1

Chinese PII Detection Model | 395M Parameters | Open Source

Model Description

OpenMed-PII-Chinese-ModernMed-Large-395M-v1 is a transformer-based token classification model fine-tuned for Personally Identifiable Information (PII) detection in Chinese text. This model identifies and classifies 54 types of sensitive information including names, addresses, social security numbers, medical record numbers, and more.

Key Features

• Chinese-Optimized: Specifically trained on Chinese text for optimal performance
• High Accuracy: Achieves strong F1 scores across diverse PII categories
• Comprehensive Coverage: Detects 55+ entity types spanning personal, financial, medical, and contact information
• Privacy-Focused: Designed for de-identification and compliance with GDPR and other privacy regulations
• Production-Ready: Optimized for real-world text processing pipelines

Performance

Evaluated on the Chinese test split (AI4Privacy + synthetic data):

Top 10 Chinese PII Models

Supported Entity Types

This model detects 54 PII entity types organized into categories:

Usage

Quick Start

from transformers import pipeline

# Load the PII detection pipeline
ner = pipeline("ner", model="OpenMed/OpenMed-PII-Chinese-ModernMed-Large-395M-v1", aggregation_strategy="simple")

text = """
患者李明（出生日期：1985/03/15，身份证号：310101198503159876）今日就诊。
联系方式：li.ming@email.cn，电话：+86 138 1234 5678。
地址：上海市浦东新区陆家嘴路123号。
"""

entities = ner(text)
for entity in entities:
 print(f"{entity['entity_group']}: {entity['word']} (score: {entity['score']:.3f})")

De-identification Example

def redact_pii(text, entities, placeholder='[REDACTED]'):
 """Replace detected PII with placeholders."""
 # Sort entities by start position (descending) to preserve offsets
 sorted_entities = sorted(entities, key=lambda x: x['start'], reverse=True)
 redacted = text
 for ent in sorted_entities:
 redacted = redacted[:ent['start']] + f"[{ent['entity_group']}]" + redacted[ent['end']:]
 return redacted

# Apply de-identification
redacted_text = redact_pii(text, entities)
print(redacted_text)

Batch Processing

from transformers import AutoModelForTokenClassification, AutoTokenizer
import torch

model_name = "OpenMed/OpenMed-PII-Chinese-ModernMed-Large-395M-v1"
model = AutoModelForTokenClassification.from_pretrained(model_name)
tokenizer = AutoTokenizer.from_pretrained(model_name)

texts = [
 "患者李明（出生日期：1985/03/15，身份证号：310101198503159876）今日就诊。",
 "联系方式：li.ming@email.cn，电话：+86 138 1234 5678。",
]

inputs = tokenizer(texts, return_tensors='pt', padding=True, truncation=True)
with torch.no_grad():
 outputs = model(**inputs)
 predictions = torch.argmax(outputs.logits, dim=-1)

Training Details

Dataset

This model was trained on a combination of:

• AI4Privacy PII Masking 200K: Multilingual base dataset (200K records across 8 languages)

• NVIDIA Nemotron-PII: Seed dataset for synthetic data generation

• Synthetic Chinese Data: ~25K high-quality samples generated with locale-specific formatting (身份证号 format, +86 phones, Chinese names, ¥ currency)

• Format: BIO-tagged token classification

• Labels: 76 BIO tags (54 entity types)

Training Configuration

• Max Sequence Length: 512 tokens
• Epochs: 3
• Framework: Hugging Face Transformers + Trainer API

Intended Use & Limitations

Intended Use

• De-identification: Automated redaction of PII in Chinese clinical notes, medical records, and documents
• Compliance: Supporting GDPR, and other privacy regulation compliance
• Data Preprocessing: Preparing datasets for research by removing sensitive information
• Audit Support: Identifying PII in document collections

Limitations

Important: This model is intended as an assistive tool, not a replacement for human review.

• False Negatives: Some PII may not be detected; always verify critical applications
• Context Sensitivity: Performance may vary with domain-specific terminology
• Language: Optimized for Chinese text; may not perform well on other languages

Citation

@misc{openmed-pii-2026,
 title = {OpenMed-PII-Chinese-ModernMed-Large-395M-v1: Chinese PII Detection Model},
 author = {OpenMed Science},
 year = {2026},
 publisher = {Hugging Face},
 url = {https://huggingface.co/OpenMed/OpenMed-PII-Chinese-ModernMed-Large-395M-v1}
}

Links

• Organization: OpenMed

Base model

answerdotai/ModernBERT-large

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