The invention belongs to the technical field of surface heat treatment, and particularly relates to a powder metallurgy automobile engine chain wheel lock pin hole laser quenching method. According to the method, the purpose of strengthening a component to be quenched is achieved by adopting gas blowing assistance and two-time un-equal speed scanning laser quenching. The two-time scanning speeds are inconsistent; the first scanning speed is low, the second scanning speed is high, and the power in the overall process is kept consistent; the gas flow is kept unchanged; during a quenching process, the gas is blown to a position of a chain wheel plane quenching light spot at a fixed angle at any time. According to the method, the properties, such as the hardness, the wear resistance, the fatigue resistance and the oxidation resistance, of a workpiece are improved, and the problems of low lock pin hole induction quenching hardness, quenching surface melting and the like are solved.