Abstract: The electromechanical installation project has a long construction period and a large amount of work. In the actual installation and construction process, it is aff ected by a variety of factors, which will easily affect the progress of the project to a certain extent, causing the project to fail to be delivered as scheduled in accordance with the contract. In order to ensure the smooth progress of the mechanical and electrical installation project, cost and cost control should be carried out in the entire construction process. Engineering cost settlement audit is mainly to strictly follow national and industry-related laws and regulations at the completion stage of the mechanical and electrical installation project, conduct a comprehensive review of the cost of the mechanical and electrical installation project, and rationally evaluate the mechanical and electrical installation project with the aid of scientific and accurate engineering cost settlement audit results The investment and output of funds can eff ectively avoid corruption in engineering projects and ensure the smooth delivery of mechanical and electrical installation projects on schedule. This article discusses the existing problems in the cost settlement audit of the mechanical and electrical installation project, and puts forward corresponding solutions based on the actual situation, and provides a reference for the development of related work.