The advantages and disadvantages of traditional gearbox fault diagnosis method based on autocorrelation, spectrum-zoom, Hilbert demodulation and cepstrum analysis are respectively analyzed. Then a gearbox fault diagnosis method is presented, which integrates autocorrelation, spectrum-zoom, Hilbert demodulation and cepstrum analysis. Finally, vibration data of the pitting gear is measured by using QPZZ-II rotating-machinery fault simulating system. The result shows that the improved method proposed in this paper is effective for the fault diagnosis of the pitting gear.This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications.. The best is to read these instructions and follow the outline of this text. Please make the page settings of your word processor to A4 format (21 x 29,7 cm or 8 x 11 inches); with the margins: bottom 1.5 cm (0.59 in) and top 2.5 cm (0.98 in), right/left margins must be 2 cm (0.78 in). We shall be able to publish your paper in electronic form on our web page http://www.scientific.net, if the paper format and the margins are correct. Your manuscript will be reduced by approximately 20% by the publisher. Please keep this in mind when designing your figures and tables etc.