Objective: To investigate the mental status, level of occupational health knowledge, health behaviors, and occupational health knowledge demand in operating and maintenance personnel in wind power plants, and to provide a basis for formulating protective measures of occupational health for operating and maintenance personnel in wind power plants. Methods: A cluster sampling was performed in regionally representative wind power plants in the wind power industry from May 2014 to June 2015, and the Symptom Checklist-90 (SCL-90) and a self-made evaluation questionnaire were used to investigate the general status, mental health, and occupational health knowledge demand in 160 operating and maintenance workers. Results: Of all respondents, 26.9% had mental health issues. The awareness rate of infectious disease knowledge and preventive measures was 11.9%. Of all workers, 96.5% wanted to know the occupational hazard factors in the workplace, and 96.3% wanted to get the knowledge of the prevention of related diseases. Conclusion: Mental health issues in operating and maintenance personnel in wind power plants cannot be neglected and there is a high demand for occupational health services and related knowledge. Comprehensive intervention measures for health promotion in the workplace should be adopted to improve working environment, enhance individual mental health education, increase the level of occupational health management, and protect the health of workers.