For the five failure modes of gears, the corresponding design criteria should be established separately. However, for the tooth surface wear, plastic deformation, etc., because there is no established calculation method and design data that are widely used in engineering and are effective, when designing the gear transmission, only the tooth root bending fatigue strength is usually ensured and the tooth surface contact is ensured. The two criteria of fatigue strength are calculated. For high-speed and high-power gear transmission (such as aeroengine main transmission, turbine generator transmission, etc.), but also to ensure that the tooth surface anti-gluing ability criteria (see GB6413-1986). As for the ability to resist other failures, although not generally calculated, measures should be taken to enhance the ability of the teeth to resist these failures.