The heavy precipitation event is simulated by the PSU/NCAR mesoscale model (MM5) in the mountain area of Shandong province. It is found that the topography of Shandong province has significant effects on the intensity of the heavy rain area. On the windward side, the divergence and moisture divergence at low level is reduced by the terrain lifting effect, and the precipitation was increased. And the divergence at the top of the mountain is increased, which leads to increase the downward vertical velocity,and reduce the precipitation. At the same time, on the leeward side, the precipitation is decreased by the reduction of the divergence.