The national census is a unified development time node and a unified method, project and questionnaire formulated by the state. In strict accordance with the instructions, relevant departments in various localities conducted a comprehensive survey and registration of the existing population in the country door by door. The focus of the census is to grasp, analyze and predict the development and changes of the existing population in various places, mainly to understand the sex ratio, birth sex ratio, single, marriageable population and elderly population. The national census also belongs to the survey of national conditions and national strength. Nowadays, the most basic scientific method of collecting population data is widely used all over the world. The data results of the national census are analyzed by the relevant departments according to the depth and progress of big data statistics, and all localities should disclose them in batches, in a timely, timely and accurate manner.