The current status of the research on the causes of grinding cracks on gear surfaces and the improvement of prevention measures at home and abroad was given by analyzing the important functions in practical conditions and structural characteristics of spiral bevel gears. It is concluded that the main causes of grinding cracks on the surface of spiral bevel gears are divided into internal cause of heat treatment process and external cause of grinding process. By analyzing the causes of grinding cracks on the surface of spiral bevel gears, the measures for avoiding the cracks in the heat treatment process and grinding process are obtained.