An orthogonal frequency division multiplexing (OFDM) visible light communication system model based on N minimum shift keying (N-MSK) mapping is established to solve challenges related to light-emitting diode (LED) nonlinearity and carrier frequency offset caused by OFDM visible light communication. The Monte Carlo method is used to compare and analyze the differences between N-MSK and binary phase-shift keying (BPSK) mapping in the performance of signal power spectral density, constellation, carrier interference ratio, and bit error rate. The experimental results reveal that the N-MSK (N>1) mapping system has superior out-of-band attenuation characteristics. In the case of the same frequency offset, the carrier interference ratio of the system is increased by approximately 15 dB using the N-MSK (N=1) mapping mode, and the ability to suppress the intercarrier interference caused by carrier frequency offset is enhanced. For the same bit error rate (10^-6), the signal-noise ratio (SNR) required by the MSK mapping system is 2 dB lower than that of BPSK mapping. The MSK mapping method can overcome the influence of LED nonlinearity on the system performance under the same SNR condition. Therefore, the proposed model has excellent signal constellation and bit error rate performance.