In this paper, in view of the problems proposed by the pilot of a certain type aircraft, such as the uncomfortable of the cockpit, the uneven air distribution of the cockpit windshield or foot heating air supply port, small ventilation of the cockpit foot supply port, the inability to increase the air supply of cockpit foot heating airport, and the freezing of the cockpit foot, we conducted cabin thermal load analysis and heat balance analysis to determine that the cause of the failure was the heating energy of the air condition itself. When flying in cold weather, the air condition system installed on the plane could not meet the requirements of the aircraft cabin thermal load. We adopt the design scheme of combining the air condition and heating system, established an efficient bleed air heating system and control system, and realized the coordination of aircraft cooling and heating function. The scheme completed the installation verification work on the plane, and the cabin comfort is obviously improved.