Health certificate is a preventive health examination certificate, which proves that the examinee has the health quality stipulated by the industry. Health certificates protect the health of employees and customers. The diseases prevented by health certificate are typhoid fever, paratyphoid fever, cholera and active tuberculosis. The examination of pulmonary tuberculosis is mainly carried out through the positive and lateral films of the chest. The examination of typhoid fever, paratyphoid fever and cholera is mainly carried out through fecal culture.