The utility model discloses a device for calculating trap parameters by measuring short-circuit current attenuation under reverse bias voltage. The device comprises a vacuum box which is internally provided with an experimental platform, wherein the experimental platform is sequentially provided with a lower electrode, a shielding layer, a test sample to be detected and an upper electrode from bottom to top; the upper electrode is connected with a direct-current charging module through a switch; a system for measuring short-circuit current under the reverse bias voltage is connected between the upper electrode and the lower electrode and comprises a short-circuit releasing free charge circuit and a de-trapping current measuring circuit which are controlled by a selective switch to be selectively conducted; the de-trapping current measuring circuit comprises a de-trapping reverse bias voltage source and a micro-galvanometer which are connected in series; the signal output end of the micro-galvanometer is connected with a computer; and the computer is connected with the selective switch. The device for calculating trap parameters by measuring short-circuit current attenuation under reverse bias voltage can be used for calculating the trap density of different level distributions of the test sample through an isothermal current attenuation theory, and an experimental result is accurate.