The invention provides a heat treatment method for improving impact toughness of 1Cr12Mo heat resistant steel. By adopting the heat treatment method, the impact toughness of blade materials or products formed by the blade materials can be effectively improved, so that the fatigue resistance of the whole blade of a turbine and the whole blade of a gas compressor can be improved, the service life of the blades can be prolonged, and the comprehensive mechanical performance of the material can be fully performed. The heat treatment method comprises the following steps in sequence: uniformly placing 1Cr12Mo blades into a common quenching charging basket based on the technology scheme; transferring the quenching charging basket into a heat treating quenching furnace for quenching and heating; and maintaining temperature and cooling in common mode. The heat treatment method is characterized in that the quenching is carried out at 900 to 940 DEG C.