Partial Transmission Sequence (PTS) is one of the effective methods to suppress the Peak to Average Power Ratio (PAPR) in Orthogonal Frequency Division Multiplexing (OFDM) systems. However, the algorithm needs a full traversal search for the best phase factor, resulting in great computational complexity. Therefore, this study proposes a PAPR suppression algorithm based on Discrete Particle Swarm Optimization (DPSO). Firstly, a new method for determining inertia weight is defined. Then the mutation operator is introduced to improve the original velocity update formula, which enhance the traditional DPSO algorithm that is easy to be premature and difficult to converge to the global optimal. The simulation results reveal that the PAPR performance of the proposed algorithm is better than that of the traditional DPSO algorithm by about 0.3 dB, and the computational complexity is lower than that of the traditional PTS algorithm.