Objective To investigate and analyze the effectiveness of case management in community prevention and rehabilitation of severe mental illness. Methods A total of 360 patients with basic stable major psychiatric illness were randomly selected from 20 communities as the research objects, they were randomly divided into experimental group and control group, each group had 180 cases. The experimental group was given case management, control group were not adopt case management because patients did not agree to attend the case management. Two groups of patients were carried out for a 22-months standardized management and then the clinical efficacy, medication compliance, trouble-making assess the situation and life quality were recorded and compared. Results In the clinical efficacy, medication compliance, troublemaking assess the situation and life quality of experimental group were better than the control group, the differences were statistically significant (P all<0.05). Conclusion The case management can effectively im-prove the life quality of mental patients, increase the therapeutic effect, maintain and promote social harmony and has obvious social benefit and economic benefit.