The invention relates to a control method and system for automobile air conditioner inner and outer circulation modes. The control method comprises the steps that the working mode of an air conditioner system is detected; the state of a compressor is detected; the air blowing mode of the air conditioner system is detected; the power state of an engine is judged; whether the conditions a, b, c and d are met at the same time or not is judged, if yes, the inner and outer circulation modes are adjusted into the inner mode, and if not, the current circulation modes are kept, wherein the condition a is that the air conditioner system is in the automatic mode, the condition b is that the compressor is in the start state, the condition c is that the air blowing mode is a non-window-blowing mode or a non-window-blowing foot-blowing mode, and the condition d is that the engine is in the power insufficient mode. According to the control method and system for the automobile air conditioner inner and outer circulation modes, the engine is prevented from working with overloads, and the service life of the engine is prolonged.