In the present paper, the material of alkaline-earth metal sulphide doped with two kinds of rare-earth metal ions was prepared by carbon reduction method, and the radiation characteristics of optically stimulated luminescence of this material are described. The PMMA dosimeter films were taken into the radiation source, then the fluorescence signal from the dosimeter films was measured with the test system build by ourselves. The relation between the radiation dose and the fluorescence intensity of the dosimeter films was obtained. The measuring range of the dosimeter was from 0.01 to 1 000 Gy (5 orders of magnitude), and there is a good linear relationship between stimulated luminescence signal value of the material and the dose. It demonstrates that this device has a good prospect. This equipment is relatively simple, small in size and low in power consumption. This device is suitable for measuring the space radiation dose exploration.