Abstract: Aiming at the problem that high peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) system in visible light communication, combined precoding and iterative clipping and filtering were applied to OFDM system based on Hartley transform, and the performance of OFDM system based on conventional Fourier transform with iterative clipping and filtering using FFT/IFFT transform was improved in this paper. According to the established system model, the spectrum utilization, PAPR and BER of different schemes were compared. The PAPR suppression effect of discrete cosine transform and Hadamard matrix precoding were analyzed. In addition, BER of filtering transformations such as FFT/IFFT, DCT/IDCT and FHT/IFHT were compared. The results show that compared with the OFDM system based on FFT, there are advantages of lower algorithm complexity and higher spectral efficiency for the OFDM system based on FHT. There are more advantages for DCT precoding technology in suppressing PAPR and improving the BER performance, and the optimal BER performance can be achieved by using iterative clipping and filtering with FHT/IFHT.