Short-wavelength radar has advantages in observing microphysical properties of cloud particles. It is a powerful device for detecting cloud —— a key member of the global water cycle. This paper briefly reviews the theoretical basis of short-wave cloud radar detection. Based on the basic principle of radar detection, with the electromagnetic scattering theory of small particles, a radar forward model (radar simulation package, RSP) is established for multi-wavelength radars and different cloud particle types. RSP is used to simulate and analyze the detection capability of three short-wave radars (X band-9.5GHz-3cm, Ka band-35GHz-8mm, W band -94GHz-3mm). Compared with the Rayleigh method, RSP method is proved to be reliable and accurate. Based on the simulation results of RSP, the power-law relationship between liquid water content (LWC) and radar reflectivity factor (Ze), effective particle radius (re) and Ze is established; a retrieval method of average LWC is also established by using Ze difference between two wavelengths at cloud base and cloud top. This paper discussed the retrieval methods of using different radar parameters to extract the microphysical parameters of liquid cloud droplets, which provides a more accurate theoretical understanding of the cloud characteristics detected by multi-wavelength radar. The RSP provides an analysis tool for the simulation of radar detection and the inversion of cloud microphysical parameters.