The modulation bandwidth of the white-light Light Emitting Diode (LED) indoor visible light communication system is limited. Under the condition that the modulation bandwidth is limited, how to further increase the communication speed becomes a hot research topic. A Multi-ary Variable Amplitude & Period Modulation(MVAPM) technique is designed. The modulation symbol structure and its symbol parameter configuration are given. The modulation methods based on On-Off Key (OOK), Pulse Position Modulation (PPM) and Digital Pulse Interval Modulation (DPIM) are analyzed and compared in terms of bandwidth requirements, transmission capacity, average transmit power, and packet error rate. The theoretical analysis and simulation results show that compared with the commonly used digital baseband modulation method, MVAPM has the characteristics of lower modulation bandwidth, higher symbol transmission capacity, symbol-free synchronization, higher modulation efficiency, which effectively improves the communication rate of the system.