Objective To explore the mediating effect of kinesophobia on pain catastrophizing and exercise compliance and the moderating effect of health beliefs in patients undergoing total knee arthroplasty. Methods By convenience sampling,364 inpatients undergoing total knee joint replacement were selected as subjects. General information questionnaire, Pain Catastrophizing Scale, Tampa Scale for Kinesiophobia, Orthopedic Patients′ Functional Exercise Compliance Scale, and the new version of Health Belief Scale were used as investigating tools. Results Pain catastrophe was positively correlated with exercise fear (r=0.540), but negatively correlated with exercise compliance (r=-0.517) and health beliefs (r=-0.314). The kinesophobia played a partial mediating role between pain catastrophizing and exercise compliance, with the mesomeric effect accounting for 46.62% of the total effect. Health belief played a moderating role in the mediating pathway between pain catastrophizing and exercise compliance (P<0.05). Conclusion In total knee replacement patients, kinesophobia has mediating effect between pain catastrophizing and exercise compliance. Health belief has moderating effect on the mediating path.It is recommended that clinical medical staff should pay attention to the influences of pain catastrophizing on exercise compliance,and help the patients improve their health beliefs, so as to promote their active participation in exercise.