With the power engineering project increasingly growing, reducing costs is becoming greatly important for power engineering project enterprises to improve the market competitiveness. In order to study the cost control management of power engineering project, firstly establish the evaluation index system; secondly evaluate the cost control management of ten power engineering project enterprises based on Entropy method and PROMETHEE method; finally analyze the results and find out the important factors that affect the cost control management of power engineering project enterprise. The result shows that management modernization is the most important factor that affects the cost control management of power engineering project enterprise, operational efficiency is the second one, and staff awareness is relatively the last important factor.