Flight load test playing a vital role in flight test is the necessary link which can evaluate the aircraft comprehensively and quantitatively. The load calibration of the traditional man-machine and small aircraft evaluate parameters need only about a dozen or dozens of key parameters. The real-time collect system channel volume is smaller, and the pressure of real-time monitoring and control system server is less. Along with the rapid development of aviation industry, the needing evaluated parameters of the large aircraft and unmanned aerial vehicles zoom to hundreds. And the collect system channel volume becomes bottle-neck. The traditional measument ways are difficult to satisfy the requirements. In view of the problem that the flight load test of mass parameters are difficult to test, the paper put forward a kind of channel multiplexing scheme, which can solve the problem that the mass parameters are difficult to test. It's verified that the scheme can be well applied to all kinds of load data measured in flight.