The invention relates to the technical field of airplane power designs and particularly provides an autonomous crosslinking control method for reduced-load starting of an airplane. The autonomous crosslinking control method comprises the steps of carrying out autonomous crosslinking control over airplane load, starting engine power and engine fuel supply regulation; additionally providing a plain/highland hydraulic unloading switching control function; starting an unloading function and airplane wheel bearing signal crosslinking; only when wheel bearing is valid and a ''highland'' of a plain/highland switch is valid, driving a relay in a starting unloading control box to act by a left starting signal and a right starting signal, and outputting an unloading signal to a hydraulic system; when the rotating speed of an engine reaches a set rotating speed or the continuous working time reaches set time, automatically disengaging a starting engine, restoring the normal pressure of the hydraulic system, making the hydraulic system realize autonomous loading control ability, and accelerating the engine to an engine slowing state by virtue of the ignition of a combustion chamber of the engine and the inertia of a rotor to finish a starting function on the ground in a highland environment.