pulse width modulation technology is proposed. Bilevel pulse width modulation is analyzed in terms of bandwidth requirement， junction capacitance and error performance， and compared with non return to zero on key modulation， pulse position modulation and digital pulse interval modulation.The results show that the two-level pulse width modulation and the non-return-to-zero on-off keying modulation have the same time slot error rate， but the additional power consumption is only M/2 of the non-return-to-zero on-off keying modulation， and M is the modulation order. Although the bilevel pulse width modulation requires higher signal-to-noise ratio compared with pulse position modulation and digital pulse interval modulation， the additional power consumption is only half of that of pulse position modulation and digital pulse interval modulation， and the bandwidth requirement is also less than that of pulse position modulation and digital pulse interval modulation， it has great advantages in power and bandwidth sensitive visible light communication system.