The internationalization of large company now is to make a profit by project contracting, so as to maintain the company operation, engineering project cost control is an important part of project contracting. Here is the project cost control in the whole process of all costs, including a lot of things, and control of each link. So there is a lot of questions to maximize corporate profits can't reach. This paper use EVC system related evaluation index such as deviation of cost and schedule variance some principles, such as to illustrate some of the cost control of the project related issues, and clearly determine the progress of the project. For a company, the largest part of the project contract is profit, 80% of companies are now using EVC system principle. So the purpose of this study is through the related principle of EVC system which is used to explain the cost control in the company cannot be maximized the benefits. So as to better help the company achieve more profits, we can also be more convenient and effective to promote the project.