An indoor visible light single-source full-duplex communication system is designed and constructed based on inverse modulation of defocused cat eye aiming at hard realization problem of all-optical communication link in indoor visible light communication system. The uplink and downlink of system are independent on each other. It overcomes the disadvantage that traditional single-source duplex communication system needs coordination of transmitter and receiver at the two ends with communication, and can realize the duplex communication of all-optical link without adding additional light source. The experimental results show that the system can realize the downlink 5.0 Mbit/s and uplink 2.0 kbit/s data transmission under the condition of 3.0 m communication distance.