The invention relates to a sliding block forced segregation mechanism which comprises a sliding block and a guide column. A sliding groove is formed in the front face of the sliding block, a sliding block positioning through hole is formed in the side face of the sliding block, an opening of the sliding block positioning through hole is formed in the inner wall of the sliding groove, a compressionblock spring device is inserted into the sliding block positioning through hole and comprises a compression block, a movable clamping pin and a spring arranged between the compression block and the movable clamping pin, and a long clamping opening is formed in the side face of the guide column. According to the sliding block forced segregation mechanism, hardware is inserted in the combining state of the sliding block and a male die, a female die guide column is guided to the sliding block positioning through hole, the female die guide column is positioned through compression block spring devices on the two edges of the sliding block positioning through hole, the sliding block is dragged to retreat in the die opening state process to achieve segregation of the sliding block, a die structure is changed to replace manpower for segregating the sliding block, manual operation is reduced, die damage is improved, the production period is improved, the plastic molding production automatic degree is improved, and the productivity is increased.