In view of the characteristics of VLC and OFDM signal modulation，this paper proposes，on thebasis of the traditional algorithm，improvements from two aspects: the timing measure function and the trainingsequence structure． Using the principle of maximum sliding auto-correlation，we can normalize energy，solveproblems of " correlation peak platform" and realize accurate positioning of symbols． The simulation results show thatthe improved algorithm can ensure the excellent timing synchronization performance and the low bit error rate ofcommunication in both AWGN channel and multipath fading channel． Especially under the condition of low signalto-noise ratio，the bit error rate of the improved algorithm is around 0． 3，while the bit error rate of the S ＆ Calgorithm is over 0． 9．