The invention discloses a full-automatic warehouse storage device and a working method thereof. The full-automatic warehouse storage device comprises a storage cabinet, wherein the storage cabinet comprises a shell, a plurality of clapboards are fixedly installed inside the shell, a plurality of taking and placing openings are formed in the front side wall of the shell, each clapboard is positioned below the corresponding taking and placing opening, a belt conveyor A is installed on each clapboard, a guiding mechanism is installed on the front side wall of the shell, a sliding platform is installed on the guiding mechanism, a belt conveyor B is installed on the sliding platform, a lifting mechanism is also installed on the storage cabinet, the lifting mechanism is connected with the sliding platform, the lifting mechanism drives the sliding platform to move up and down along the guiding mechanism, a regulating mechanism is also installed in the storage cabinet, each belt conveyor A isconnected with the regulating mechanism, and the regulating mechanism controls the operation of each belt conveyor A. The full-automatic warehouse storage device and the working method thereof aim tosolve the problems that the height of a storage rack is limited, the use space is wasted and the labor intensity of a worker is too large due to the fact that goods are taken and placed manually, anddanger is caused when the worker climbs high at present.