An embodiment of the invention provides a radioactive sample activity detecting system which comprises a conveying device, a detecting device, a communication regulation device, a data collecting device and an upper computer. The conveying device is used for conveying at least one sample. The detecting device is located on the conveying device and is used for detecting the radioaction of at least one sample and outputting detection data. The communication regulating device is used for receiving and processing the detecting data. The data collecting device is used for receiving the processed the detecting data from the communication regulating device and outputting the collected data. The upper computer outputs control signals to the conveying device, the detecting device and the communication regulating device and receives the collected data output by the data collecting device. The radioactive sample activity detecting system reduces measuring errors brought by individual difference of detectors, realizes simultaneous measurement of a plurality of detectors so as to improve the efficiency and the precision of radioactive sample activity detection.