Considered the effect of temperature on the main bearing, the temperature distributions of journal, bearing and lubricant were calculated, and the thermo hydrodynamic performances of the main bearing were analyzed by solving generalized Reynolds equation, energy equation and solid heat conduction equation, etc.. The results show that the bearing has obvious effect on the temperature of lubricating oil film, maximal film pressure, leakage flow rate of ends and misalignment moment. The surface roughness and viscosity - pressure effect of lubricant have a great influence on the lubrication performance of misaligned journal bearing with larger eccentric ratio.