The invention provides a hybrid filtering method for the multi-source noise of a gyroscope and a test platform. The test platform comprises a real-time simulation target machine, a triaxial rate rotary table, a triaxial gyroscope, a star sensor, a star simulator, an attitude determination module, an attitude control module and an executing mechanism. According to the hybrid filtering method for the multi-source noise of the gyroscope, the device noise of the gyroscope is suppressed through H2 optimization, and the modeling error of a filtering system is inhibited through H-infinity optimization. In combination with the H2 optimization and the H-infinity optimization, a hybrid filter is designed, so that the estimated error meets the requirement of a performance index. The hybrid filtering method designed for the multi-source noise of the gyroscope effectively improves the accuracy of the attitude determination. Based on the method, the attitude determination module of the test platform is running in real time. The test platform is directed to verify the effectiveness and the engineering practicality of the hybrid filtering method for the multi-source noise of the gyroscope, thus being applicable to the ground simulation verification in the aerospace field.