Three dimensional pressure distribution and temperature field of the bear in water lubrication and its difference between the bear in oil lubrication were analyzed in numerical simulating through solving the law-of-the-wall and Reynolds equation with finite elements method (FEM), and the changes of lubricant viscosity with temperature were taken into account. The result showed that under high speed condition, pressure distribution and temperature field of the bear are different from those with oil lubrication and also could control the temperature of bear effectively with water lubrication.