The frequent fluctuations of equipments and materials prices have serious influence on the investment and cost control in power grid project. In order to accurately grasp the trend of equipment prices and reasonably control the project cost, it has positive significance to research the influence factors on equipment prices. Combined with the equipment price and the bidding data, these factors are analyzed in this paper, which are divided into three types: policy factors, economic factors and enterprise behavior. The factors affected the equipment prices are mostly through two aspects: cost and profit. Finally, the factors influencing profits could be concluded in three aspects, supply-demand relationship, competition model and bidding strategy; while the cost is mainly concluded into raw material cost, labor cost, fixed cost, development cost and financing cost. The research could provide references for the reasonable control of project cost and the reduction of project investment risk.