In this paper, we mainly design a network protocol stack and a radiation detection system under the radiation emergency condition for humanitarianism succor. In the network protocol stack, a novel stop and wait algorithm is introduced to a new medium access control protocol in designed radiation system. The system consists of sensing nodes, which contains $$\upgamma $$ detector and GPS localization function, the relay and gateway nodes with a long communication distance, and an information treatment center for further radiation analysis. Based on the system, large numbers of experiments are performed. From the performance evaluations, it can be concluded the proposed protocol stack and designed radiation detection system is applicable to the wireless sensor networks with less energy consumption, and the radiation detection network is valuable for the treatment of radiation emergency with low localization error.