Abstract: In the Orthogonal Frequency Division Multiplexing (OFDM) systems, based on the studying of Peak to Average Power Ratio (PAPR) reduction by using Partial Transmit Sequence (PTS) technology, an improved PTS scheme of multi-stage optimization is proposed. This method is to find the optimal phase rotation factors by increasing the number of optimization steps and reducing the number of pre-determined phase elements in the set of each step, and change the trend of computational complexity which is higher with more disjoint sub-blocks and more predetermined phase factors. This method can be used in conjunction with suboptimal search algorithm. Analysis of computational complexity and simulation results show that, compared with traditional scheme, this method can not only largely reduce the computational complexity, but also reduce the PAPR.