Abstract: In recent years,violence in hospital venues has occurred frequently,and the violence of the patients has become more and more serious. For the interests of both doctors and patients,social orientation and social stability,medical violence have caused a very bad negative impact. How to effectively alleviate the doctor-patient conflict and to prevent medical violence has become a focus of academic issues. This paper takes the patients and their families who have experienced medical service failure as the empirical research object. From the perspective of patient behavior,through the fuzzy set qualitative comparative analysis,this paper studies the driving factors and the predecessor of the violence of the affected people. The results show that Machiavelli,medical quality and kinship are the key elements of the patient aggressive behavior. Machiavelli characteristics,the degree of illness and the hospital environment will affect the patient's aggressive behavior through the way of change. Only when the medical-related factors combine with the patient-related elements through a specific form,the patient will have a higher aggressive behavior intention.