Water and fire protection design in buildings is a very critical part of construction projects. The main purpose is to effectively prevent fire hazards, and to conduct fire control in a timely manner when a fire accident occurs suddenly. The related design is very critical. Requires relevant workers to attach great importance to it, strengthen the design of upgrading water supply and drainage fire-fighting facilities, and strictly control the construction quality to ensure the safety of residents’ lives and property. Therefore, the article integrates the actual situation of the construction project, focuses on explaining the problems that should be paid attention to in the water supply and drainage and fire protection design work of the building, and proposes effective measures to control the construction quality, hoping to provide some help to relevant workers.