Named entity is the main carrier of relevant medical knowledge in Electronic Medical Records （EMRs），so clinical named entity recognition（CNER） has become one of the basic and crucial tasks of clinical text analysis and processing. Due to the particularity of medical text structure and Chinese language，the recognition of clinical named entities for Chinese EMRs still faces great challenges. In this paper, a Chinese clinical named entity recognition method based on multi-head self-attention neural network is proposed . In this method, a character-level feature representation method combined with a domain dictionary is presented. Moreover, based on the BiLSTM-CRF model, a multi-head self-attention mechanism is incorporated to accurately capture the multiple features from different aspects, such as dependency weights between characters and contextual semantic relationships, thereby effectively improving the ability of Chinese clinical named entity recognition. Experimental results demonstrate that the proposed method outperforms other existing methods and has the best recognition performance.