A tie down assembly suitable to mount in the structure includes a cup, a cross-shaped crossbar that is fastened removably to and positioned within a recess of the cup, and a disc shaped plate that is fastened removably to the cup and/or the crossbar. The crossbar is fastened to the cup by a plurality of fasteners, while the plate is fastened to the cup and/or the crossbar by at least one fastener. The cup is installed within a hole formed within a first surface of a structure, and the plate is positioned against an opposite surface of the structure. When the plate is attached, a compressive load is introduced and squeezes the first and second surfaces of the structure together, such that most of the load is borne down the center of the fastener attaching the plate. The tie down module structure adopting the invention can bear heavier load and can be very easy to repair and replace.