The invention relates to a testing device and method for current measuring in the potential shifting process of helicopter extra-high-voltage hot-line work. The testing device comprises a whole helicopter work body and an insulating supporting platform. The whole helicopter work body is arranged on the insulating supporting platform, a current testing device body is further arranged on the insulating supporting platform and the current testing device body is connected with the whole helicopter work body through a wire. A metal probe bar is arranged in a dummy, the front end of the metal probe bar is close to a testing simulation wire, the rear end of the metal probe bar is connected with the input end of the current testing device body, and the output end of the current testing device body is connected with a ground data processing terminal. A distance needed by testing exists between the testing simulation wire and the metal probe bar, and the testing simulation wire is connected with a testing transformer. The testing device and method can meet the testing requirements for current measuring in the potential shifting process of helicopter extra-high-voltage hot-line work and the like.