The present invention discloses a management method of power engineering cost, including: 1) collect and collate the historical power engineering data, and establish engineering sample database; 2) Explore the factors influencing power engineering cost and construct the cost factor associated topology; 3) identify the price transmission path; 4) Establish the power engineering cost change trend model based on the factor distribution on the price transmission path, and conduct training on the model combined with the historical data, to solve the set of cost change trend of the equipments and materials required in the current stage of engineering. By considering the effect of market price fluctuation on the price transmission of required equipments and materials, this invention can propose appropriate management control program for the next stage of engineering costs more clearly, further shrink the deviation of cost, reduce the investment risk of power engineering and improve the dynamic control system of power engineering.