In the environment of the lowest price winning the bid, competition among the hydroelectricity construction enterprises has become increasingly fierce. For the sustainable development, they have to take low profit margins, even at the cost price for the successful bid. So the cost management, as one part of reducing expenditure of the hydroelectricity construction enterprises, is important. According to the investigation of the current situation of the cost management of The Three Gorges Company Gezhouba Group Co., Ltd, this paper proposes the method establishing the cost analysis database and the concrete steps, intending to improve the efficiency of the cost accounting and analysis by means of the information technology, and win the bidding competition advantages for the hydroelectricity construction enterprises. Meanwhile, this paper hopes that the measure has some reference value for the same industry.