Prevention of occupational diseases has three levels of prevention principles, the first level of prevention in the etiology of hazardous factors eradicated; the second level of prevention early detection and diagnosis of early treatment; the third level of prevention is the timely treatment of prevention and control of complications. 1. Primary prevention: preventing occupational diseases from occurring fundamentally, replacing toxic production substances with non-toxic ones, rationally organizing and arranging the labor process, formulating a reasonable labor system, doing a good job in safety and health publicity, regular and timely medical checkups, and exercising to improve the body’s immunity. 2. Secondary prevention: regular medical checkups for people with occupational diseases, early detection and diagnosis, early treatment, and control of diseases at an early stage. 3. Tertiary prevention: patients who have already suffered from occupational diseases should be treated scientifically and effectively to prevent and control the occurrence of complications and minimize the occurrence of complications and disabilities. Once practitioners have abnormal physical symptoms, they should go to the hospital for examination in time to avoid delaying treatment.