An apparatus for the preparation of pulp molded plate includes a press and a three-piece mold including an upper die (1), a surrounding frame (2) and a lower die (3), wherein one of the dies is a moving die and the other is a fixed die, and lower die is always within the press, and moves in relation to the upper and lower dies. The apparatus also includes a rigid matrix and a flexible punch with a retractable die bar, which are installed respectively on the upper die and lower die, so as to prepare a heterotypic pulp-molded plate with a convex part. Also disclosed is a pulp molded plate prepared by this preparation apparatus.