Preclinical studies of medical devices are the important parts of risk management of medical devices. During the course of preclinical study of the medical devices, human factors are important to affect reliability and the effectiveness of preclinical studies. This article discusses the development of human reliability study and human reliability analysis methods. We analysis the related factors of human reliability in combined with the characteristics of preclinical studies of the medical devices. We put forward the proposals and measures in how to improve the human reliability in preclinical studies in the medical devices