High altitude contra-rotating propellers are increasingly being utilized in High Altitude Long Endurance (HALE) aircraft, due to the significant improvement in aerodynamic efficiency of contra-rotating propellers compared to conventional propellers. This study compares the accuracy of the Multiple Reference Frame (MRF) quasi-steady calculation method with the unsteady calculation method, and employs the MRF quasi-steady method to analysis the effects of axial distance, twist angle, and the rotational speed ratio on the performance of contra-rotating propellers at high altitudes. The results indicate that within the studied range, an increase in axial distance leads to a slight improvement in the efficiency of the contra-rotating propellers, although the overall enhancement is minimal. Additionally, minor variations in the twist angle of the front and rear propellers are advantageous for enhancing the aerodynamic efficiency of the contra-rotating propellers. The maximum efficiency of the contra-rotating propellers is achieved when the rotational speed ratio is 1.05.