Based on the time autocorrelation characteristics of weather radar, the end to end I/Q signal simulation algorithm is established using the feuillete′ model. Statistical characteristic is analyzed to verify the reliability of the algorithm. The results show that simulated I/Q signals follow the gauss random distribution, and Echo Power obey exponential distribution, which are consistent with the statistical characteristics of the real weather radar echo signal; By using the weak precipitation data of Nanjing University"s C-band dual polarization weather radar, simulation signal and real signals are comparative analyzed, statistical results showed that under similar parameter settings, the statistical properties of standard deviation of reflectivity factor and speed between simulation and real signals are basically the same, and are basically consistent with the theoretical formula.