In order to consider the feasibility of practical implementation and reduce the complexity of OFDM systems, an improved SLM algorithm is proposed. The original data are segmented and scrambled, which breaks the correlation of the original data sequences, and reduces all sub-carrier phase coherence, thereby reducing the OFDM system PAPR. Following the linear nature of the Fourier transform, the obtained IFFT data sequences are linearly combined to get the new scrambling code sequences, such that strictly controlling the IFFT number, while getting more data sequences, which further reduces the system PAPR, and significantly reduces the computational complexity of the system. Theoretical analysis and simulation results show that the improved SLM algorithm can effectively suppress PAPR, while reducing the algorithm complexity and system complexity.