In the context of rapid urbanization and industrialization, the demand for distribution network engineering construction is constantly increasing, and cost control of distribution network engineering is currently one of the key issues of concern. The engineering cost may be influenced by multiple factors such as market price fluctuations and changes in construction scale. Identifying the main influencing factors for key control can effectively improve the accuracy of cost prediction. It is focused on the cost of overhead line engineering in the distribution network, and empirical research is conducted based on sample data in Shanghai. Through data analysis tools, it provides assistance for the cost of overhead line engineering in the distribution network in Shanghai. Firstly, the cost deviation based on the engineering balance rate is analyzed.Secondly, the principal component analysis method is used to screen out key influencing factors from the numerous factors affecting the cost of overhead line engineering in the distribution network, which helps relevant units of power engineering to better control the cost and reduce deviations.