Abstract: A bearing testing machine has been designed specific to the tests on rotation speed, load, torque, temperature rise and life of the flexible bearings for harmonic drive gear reducer. With horizontal structure, this testing machine could simulate the actual operating conditions of the above-mentioned bearings. In this testing machine, servo motor is used to control the rotation speed accurately; test bearing could be loaded on axial and radial directions stably through using hydraulic proportioning valve; NI-PXI platform is used to realize automatic control and data acquisition; LabVIEW is applied to develop environment design, acquisition and control system software. The testing machine could automatically operate in accordance with the pre-set load spectrum, having the functions regarding parameter display including rotation speed, vibration, temperature and pressure, alarm against upper and lower limits, and automatic protection. The results of the test show that this testing machine could operate stably with high reliability, so that it could meet the requirements of tests on various models of bearings, which would provide reliable data support for the structure design and process improvement of this series of bearings.