In visible light communications, multipath effects and channel attenuation in traditional orthogonal frequency division multiplexing (OFDM) systems can generate intersymbol interference and reduce system reliability. In order to guarantee the quality of communication, OFDM system with cyclic prefix was used to resist the symbolic interference caused by multipath effect. In order to reduce bit error rate(BER) and peak-to-average power ratio(PAPR) of the system, Haar wavelet was used to optimize the performance of system parameters such as validity, reliability and PAPR. Monte Carlo method was used to verify the simulation results. The results show that, when bit error rate of the system is 10-4, BER performance of discrete wavelet transform OFDM system is about 5dB higher than that of fast Fourier transform OFDM (FFT-OFDM) system. Communication efficiency has been improved by about 11%. When PAPR of the system is 5dB, complementary cumulative distribution function (CCDF) of FFT-OFDM system is close to 10-2. CCDF value of DWT-OFDM system is 0. This study provides a reference for OFDM communication based on visible light wavelet transform.