In the multi-market environment, the  total income of power suppliers is affected by the market mechanism, service cost, service price and market capacity distribution of major energy market and auxiliary service market in which they participate. At the same time, the  bidding strategies of archrivals have a significant influence on the profit, resulting in the fact that the optimal decision-making process of the multi-market capacity distribution of power suppliers is full of great uncertainty. Fuzzy game theory and fuzzy optimization theory were combined to establish a  joint bidding decision model
for power suppliers in major and auxiliary service markets. Multi-objective optimization was completed, and simultaneously the problem of uncertainty and the competition game relationship between power suppliers were fully considered. Using the established model, under certain background, the determination of the corresponding bidding strategies in major/auxiliary market according to the optimal fuzzy game balance for the power suppliers was further discussed.