Masks are important to prevent respiratory tract exposure. Correct selection and wearing of masks can reduce the risk of respiratory-borne viral infections such as 2019 novel coronavirus (2019-nCoV). The protection level of mask using will be affected by the types of mask, the face shape, the occupational nature of the crowd, the working environment and the correct wearing scheme based on the national standard, industry standard, diagnosis and treatment plan and other relevant data or research results, this paper discusses the key points of the selection and wearing of masks for different occupational groups, so as to provide reference for different groups to apply correct respiratory protective measures, and reduce the exposure risk of various groups and facilitate the control of epidemic situation.