The utility model relates to an exploitation and manufacturing field of counting type ray detection device, in particular to a radioactive material detection system in the detection system, which comprises a detector with the characteristic of ray energy, an electronics amplifier, a data collection card, a digital thresholding controller, controlling, measuring, counting database and ray display; wherein, the electronics amplifier is a digital bi-energy window electronics amplifier. The utility model not only guarantees the high sensitivity of the system to radioactive material detection but also makes the system have identifying function to the energy area of the radial detected, and has the advantages of simple design, good compatibility, wide application, no need of complex devices and low cost, and is conveniently used in various counting type ray detection system.