The invention discloses an electromagnet toothed-plate fluid-core turnover mechanism for a stacker crane. The mechanism comprises a turnover electromagnet casing and a fluid-core toothed plate connected with the turnover electromagnet casing in a turnover way, wherein supporting seats are arranged on the side wall of the turnover electromagnet casing; the supporting seats are connected with the fluid-core toothed plate through a turnover shaft; the fluid-core toothed plate comprises two parts, namely a serrate plate with a cavity therein and a counterweight core arranged in the cavity; when an electromagnet stays in a positive stacking state, the fluid core flows to the serrate side of the serrate plate, and the gravity center of the fluid-core toothed plate is below the turnover shaft; and when the electromagnet stays in a negative stacking state, the fluid core flows to the side of the serrate plate, which is far away from the serrate side, and the gravity center of the fluid-core toothed plate is below the turnover shaft. According to the mechanism provided by the invention, the fluid-core toothed plate is hinged to the turnover shaft, and can turn over as the electromagnet casing turns over by virtue of the counterweight core moving in the serrate plate.