In order to predict the temperature field distribution and thermal load characteristics of the hydro-viscous clutch, the convective heat transfer coefficient of the heat dissipation surface of the friction pairs was obtained by numerical simulation. The fluid-solid coupling finite element model of the friction pairs was established by using CFX, then the temperature field distribution of the friction pairs was obtained. The internal relationship between the factors and the convective heat transfer coefficient was revealed by taking the shape of the heat exchange surface, the speed of the friction disk, the velocity of oil and inlet pressure, and the physical properties of the fluid into consideration. The results showed that the temperature of friction pairs increased gradually from the inner diameter to the outer diameter, and the center temperature of rhombus area was higher than that of the surrounding area. The greater the rotating speed of the friction disk, the greater the convective heat transfer coefficient; the smaller the oil viscosity, the greater the inlet pressure and the greater the convective heat transfer coefficient. It can be seen that the effect of oil velocity on the heat transfer coefficient was most significant. The rotating speed of friction disk, inlet pressure and viscosity of oil could change the flow velocity and condition, thus affecting the convection heat transfer coefficient.