Using the data from the Parsivel laser precipitation particle spectrometer combined with rainfall data and radar data, we analyze the structure characteristics and difference of raindrop spectrums of two heavy rains in Shouxian. In addition, the relationship between rain intensity and radar reflectivity factor is fitted. Results show that the rainfall intensity directly affects the characteristic parameters of the raindrop spectrum, and increases with the rainfall intensity. In the Meiyu front rainstorm, contributions to the total number concentration of raindrops with a diameter of 0.25 to 1.0 mm are the maximum, and rainfall intensity is the greatest. In the typhoon rainstorm, the contributions to the total number concentration of raindrops with a diameter of 0.75 to 1.0 mm are the greatest, but those to the total rainfall intensity of raindrops with a diameter of 1.0 to 1.25 mm are the greatest, which indicates that the larger particles contribute more greatly to the heavy rainfall; The ZR relationship of the Meiyu front rainstorm is 〖WTBX〗Z〖WTBZ〗=160〖WTBX〗I〖WTBZ〗1.47, and the 〖WTBX〗ZR〖WTBZ〗 relationship of the typhoon rain is 〖WTBX〗Z〖WTBZ〗=152〖WTBX〗I〖WTBZ〗1.30.