Based on the vertical velocity data of wind profiler and the minute level precipitation data of AWS in 2014, the relationship between the vertical velocity and the ground rainfall is discussed by using the polynomial nonlinear fitting method. The minute level data of both vertical velocity and precipitation of rainfall events shows that the vertical velocity threshold is a good clue for rainfall start, end time and rainfall intensity. The results show that vertical velocity can reflect the falling velocity characteristics of the raindrops. According to the analysis on each layer, the goodness-of-fit of the rainfall and the vertical velocity regression equation at the height of 700 m is the most stable, and the other layers have different goodness-of-fit in each season. Although the value of the vertical velocity cannot predict rainfall intensity quantitatively, it can be used as an obvious indication for the fluctuation of rainfall intensity through the entire process. The vertical velocity at 700 m level is the most stable indicator for rainfall forecast. The indication of vertical velocity for precipitation can be used for early warning and nowcasting of severe weather, such as heavy rain, hail, snowfall. The vertical velocity threshold is determined by the precipitation phase, temperature, humidity, turbulence and so on. But it is not the only indicator.