The prediction and calculation of rain attenuation is one of the key problems of satellite communication in Ka-band. The model of DAH rain attenuation prediction in Ka-band is analyzed and its calculation procedure is summed up. Based on Wiener prediction, a new predictive model of rain attenuation, which enjoys the advantages of relatively simple structure, the ease of iteration and simple calculation amount, is established. Its concrete algorithm and procedure are also given. The simulation results show that the characteristics of this mew model are almost the same as those of DAH model under horizontal, vertical and circular polarized modes. The predictions in different regions are also consistent. The maximum deviations between this new model and DAH model are no more than 0.065 dB and 0.005 dB respectively when the orders are 2 and 3. These demonstrate that the new model proposed is available for use, effective, simple in algorithm and easy to be applied in engineering.