With the advancement of carbon?neutral goal and the deepening of electricity market reform, it is of practical significance to study multi?agent game on power generation side of electricity wholesale market to improve renewable energy permeability. Aiming at asymmetric market position, a Cournot?Bertrand hybrid game model considering market share preference with carbon transaction cost is established. Performing mathematical reasoning and numerical analysis, equilibrium characteristic value and local stability region are given. Finally, the influence of carbon emission coefficient, horizontal difference parameter and market share preference parameter on equilibrium is studied. Simulation examples show that with the decrease of horizontal difference parameter, market profits are significantly reduced, and electricity output of thermal power generation suppliers shows a U?shaped trend. Considering market share preference, profit?seeking power generation suppliers will take the competitive strategy of controlling power supply and raising electricity price to maximize profits.