The public electricity part of this project includes: electricity for elevators, electricity for multi-storey office buildings, electricity for domestic water pumps, electricity for gardens and architectural landscapes, electricity for firefighting, electricity for public lighting, sewage equipment, street lamps and other lighting loads And power load. The calculation load is mainly based on office buildings and commercial areas. For other loads, the required coefficient can be found in Table 5. The formula mentioned in 2.2.2 is used to calculate the load for each electrical equipment. The calculation results are shown in the appendix.It can be seen from the original data that the installed capacity of the office building and commercial area are 208KW and 261KW respectively, and the calculated load is calculated according to the need coefficient method.