Propeller is the most important aerodynamic part in the UAV system, but the effect of checkout method of UAV’s propeller by measuring rotate speed using piston motor in ground condition is not good in fact. The test rotate speeds are not centralized into the standard range of rotate speed as anticipant, but distributed symmetrically. The check plan of propeller is usually delayed by this reason in actual. The aerodynamic characteristics of propeller are decided by the shape, and the disturbances of slipstream are ignored in this test method using piston motor in ground condition. Accordingly, in basic of results of rotate speed measured by piston motor in ground, wind-tunnel test is used to measure the aerodynamic characteristics of propeller in different velocities and rotate speeds, and flight emulate method is used to compute flight capabilities of the same UAV after using these propellers. Finally, improvements on checkout method of propeller are provided, by analysing wind-tunnel test data and flight emulate results.