The principle and implementation of the spectrum spreading and scrambling code in the TD-SCDMA system has much difference with that of other 3G standards, the TD-SCDMA standard brings the principle and realization of complex spectrum spreading and complex scrambling code. However, none of the relevant materials has given out its working principle, schematic diagram and performance analysis. Not only the specific principle of those techniques in TD-SCDMA and its implementation schematic diagram would be given in this paper, but also its improved scheme would be presented. Then, performance analyzing and comparison are done by the related simulation results.