Market power evaluation and surveillance is one of the most important contents to ensure the effective operation of electricity market. A mechanism that can greatly improve the supervising and managing efficiency is proposed. First

according to the SCP analysis frame (market structure

market behavior

market performance) in the industrial economics

the index systems to evaluate the market power level of the entire market and the market power of specified generation company separately are constructed. Secondly

a fuzzy hierarchy comprehensive evaluation method is presented to evaluate the market power warning levels of the market

congestion areas and specified generation companies in real time. Then

according to the evaluating result of SCP

the monitor map is painted with different colors and the corresponding supervision decision is made to the link of problem in time. Finally

using the historical market data of a real electricity market

it is proved that the market power warning and surveillance decision-making mechanism based on SCP model proposed can effectively identify the market power level of S

C

P and the tactical bidding behaviors of generation companies.