In view of the limitations of shear line identification products of CINRAD-CD weather radar, the detection data in the missing detection area are effectively filled by means of median filtering, moving average, and other preprocessing methods. Then, the radial shear, azimuthal shear, and vertical shear of the radial velocity of the wind field are calculated by using the least square fitting method, and the radial and azimuthal combined shear of the wind field is further obtained, so as to obtain the vertical shear diagram. Through the two examples of precipitation process in Yinchuan, it is proved that the above method can identify the wind shear line more accurately and can provide more scientific reference for nowcasting.