Based on the SLM algorithm

an improved algorithm is proposed to reduce the Peak to Average Power Ratio（PAPR）in the Visible Light Communication（VLC）system.Using improved Logistic chaotic sequence as superimposed training sequence

and the random phase sequences in this algorithm

the system doesn’t need to transfer all the random phase sequences

which only need to transfer the initial value of chaotic sequence.At the receiver side

the chaotic sequences can be recovered according to the initial value.Therefore

this algorithm can reduce the redundancy of the side band information and improve the bandwidth utilization rate and BER performance of the system.The principle of the algorithm and simulation results are given in this paper.The simulation results show that the new algorithm can effectively suppress the PAPR of the VLC system

and improve the SNR of the system.