Abstract: In order to analyze the thermal scuffing failure under heavy load, the thermal behavior due to friction power loss was investigated in mixed lubrication regime for spiral bevel gears. This method integrated the mixed elastohydrodynamic lubrication (EHL) analysis results with the finite element method (FEM) based on thermal analysis. The EHL model of point contact was conducted to solve the friction and heat flux along the contact path by taking into account the machine roughness, load shearing, velocity vector and contact geometry. A single tooth model form FEM was utilized to analyze the bulk and flash temperature by considering the heat conduct and heat convection. Comparative analysis of scuffing load capacity using ISO 6336-20 standard and FEM results for spiral bevel gears was carried out. The results show that the variation of temperature solved with conjunct method was under the ISO standard, and the change law of FEM results was very close to the ISO standard. In theory, the conjunct method solved the heat flux and temperature was more coincident with the actual work condition under heat conduction and heat convection. The ISO standard was weak in solving above mentioned peculiarities and bulk temperature, but it had wide applicability. It was useful to integrate the finite element thermal analysis with ISO standard for estimating the load capacity of spiral bevel gears in economy and applicability.