A wireless data communication system and method are illustrated. The wireless data communication system has a central communication device and multiple communication devices, wherein the communication devices are able to communicate with the central communication device. The central communication device requests one of the communication devices to transmit one or more packets to the central communication device; if the central communication device determines at least one of the packets of the communication device is lost during transmission, and another one of the communication devices receives the one or more lost packets of the communication device, the other one communication device retransmits the one or more lost packets of the communication device to the central communication device after being requested by the central communication device. Thereby, the retransmission efficiency of packet loss can be enhanced and the transmission efficiency of radio frequency can be improved.