The invention discloses a flat-plate window-shaped plastic pallet. The flat-plate window-shaped plastic pallet comprises an upper plate and supporting feet, wherein the upper plate comprises an upper plate body, and nine pallet inserting heads which are integrally formed below the upper plate body; the upper plate body is a quadrate flat plate, and grid ribs are arranged on the lower surface of the upper plate body; a plurality of quadrate through grooves in which reinforcing steel bars are inserted are formed in four sidewalls of the upper plate body; the pallet inserting heads are correspondingly uniformly distributed in three ranks and three rows in the transverse direction and the longitudinal direction; each supporting foot comprises a window-shaped grid style supporting foot body, and a pallet inserting seat which is integrally formed on the supporting foot body; the position of each pallet inserting seat on each supporting foot body is adapted to the position of each pallet inserting head below the upper plate body; inserting grooves of which the shape and size are adapted to those of the pallet inserting heads are formed in the top parts of the pallet inserting seats. According to the flat-plate window-shaped plastic pallet, a cover plate is arranged and can cover grooves when a user requires to change the top surface of the upper plate into a smooth and flat surface; a steel plate is inserted into the upper plate, so that the bearing capacity can be improved.