Gears with highspeed and heavyload always run in mixed lubricating conditions． Ｒough surfaces of gears experience heavy friction and high flash temperature，resulting in larger energy loss and accelerating surface wear failure． In order to predict tooth wear rate accurately under mixed lubricating conditions，a new wear analysis model is proposed so that it can accurately describe the process of wear in mixed lubricating area in a microscopic dimension． Before the implementation of wear analysis program， the effect is considered of a coupling thermo-elasto-hydrodynamic phenomenon in the contact area． Methods in the mathematical model of tooth wear have been pro

posed to decide parameters in the model and its application range is discussed． By studying the performance of spur gears in terms of contact situation，pressure distribution，rise of flash temperature，lubricating state，friction and wear trend， it is revealed that the tooth surface wear is affected by miscellaneous factors，and its distribution on the tooth surface is also nonlinear． The temperature rise will greatly change the lubrication and friction interface in the mixed lubricating state． At the same time，asperity contact effects bring about a larger local wear rate and violent fluctuation，and further exacerbate wear degree of the tooth surface． Finally，comparison between the prediction wear depth and the experimental measurements indicates close congruity． The verification of the gear wear test indi

cates that the prediction model can provide evidence for gear design and engineering application．