The invention provides a method for determining a throughput rate of a wireless network retransmission broadcast mechanism under transmission time limit. The method comprises the following steps: determining the probability of successful broadcasting of broadcast data without using a response mechanism in the transmission time limit, determining the probability distribution of the average servicetime of the broadcast data in the transmission time limit, and then determining the throughout rate of the wireless network retransmission broadcast mechanism under the transmission time limit. Through the method provided by the invention, the throughput rate of the retransmission broadcast can be accurately predicted according to the network parameter, thereby providing help for the effective implementation of the wireless network retransmission broadcast mechanism.