Abstract In order to process the non-stationary vibration signals such as speed up or speed down effectively, this new method, which combined order tracking technique with singular spectrum denoise, are presented to diagnose the early stage fault signals of gearbox. Firstly, the vibration signals are sampled at constant time increments, and then used software to resample the data at constant angle increments. Therefore, the time-domain transient signals are changed into angle-domain pseudo-stationary ones. Second, the signals in angle-domain are analyzed with singular spectrum denoise. At last, the signals after denoising are analyzed with order tracking analysis. The experimental results show that combined order tracking analysis with singular spectrum denoise can effectively diagnose the faults character of the gear through analyzing the early stage fault signals of gearbox.