Based on the electrical design principles of commercial buildings, this paper analyzes the key points of electrical design of commercial buildings, including defining the design requirements of commercial buildings, ensuring the reliability of electricity use, designing reasonable metering methods, marking the details of electrical design, etc. By studying the key points of power distribution equipment installation, pipeline laying construction, switch, socket installation, lightning protection and grounding system construction, emergency lighting system construction, project safety management and other points, its purpose is to optimize the operating environment of the electrical system in commercial buildings and ensure the safety of the electrical operating environment in commercial buildings.