Multi-polarized antenna systems are capable of reducing device size while maintaining low inter-antenna correlation, and thus have great potential for wireless communication systems of small UAVs. A polarization Multi-Input Multi-Output (MIMO) channel model is proposed based on the geometric theory of double cylinders. The geometric method is used to simulate channel depolarization, where the MIMO signal strength of the scatterer is determined by a simplified ray tracing method. The modeling method provides a mechanism for analyzing and calculating the MIMO polarized Channel Impulse Response (CIR), which can further deduce the time-frequency characteristics of cross-polarization discrimination (XPD) and MIMO channels. In addition, numerical simulation analysis of appropriate modeling parameters is performed.