A wall panel installation structure and installation method thereof is disclosed, which wall panel installation structure comprises two or more wall panels, wherein a locking structure is configured on the wall panel and adhesive assemblies disposed on a back surface thereof. The locking structure comprises a locking protrusion strip and a locking groove engaged with the locking protrusion strip. The adhesive assembly comprises a substrate, adhesive disposed on two sides of the substrate, and release papers covering outer sides of the adhesive. Adjacent wall panels are locked with each other through the locking protrusion strip and the locking groove, and the wall panels are attached to a wall surface through the adhesive assembly after removing the release papers. The wall panel installation structure of the present invention can enhance integrity and prevent warping deformation, thereby simplifying on-site construction procedures while ensuring firm adhesion.