The invention discloses a split combined type decoration integration heat preservation wall plate and an installation technology thereof. The split combined type decoration integration heat preservation wall plate comprises a decoration composite plate and a keel composite integration plate, and further comprises a connecting plate connecting the decoration composite plate and the keel composite integration plate. A plurality of decoration composite plates are sequentially arranged on the front side face of the keel composite integration plate in the vertical direction. The decoration composite plates comprise panels, punching plates, steel angles and first heat preservation layers. The back faces of the panels are bonded to the punching plates. Fold edges are arranged at the peripheries of the punching plates. The steel angles are arranged on the inner sides of the left and right fold edges of the punching plates. The first heat preservation layers are arranged on the back faces of the punching plates. The keel composite integration plate comprises a keel frame, an aluminum back plate and a second heat preservation layer. The back face of the keel frame is connected with the aluminum back plate. The keel frame comprises two parallel longitudinal rods and a plurality of transverse rods vertically arranged between the longitudinal rods. The second heat preservation layer is arranged among the longitudinal rods and the transverse rods in a filling mode. The front and rear ends of the connecting plate are correspondingly connected with the steel angles and the longitudinal rods by dovetail screws. The split combined type decoration integration heat preservation wall plate has the advantages that intensity is high, security and heat preservation are achieved, energy savingand environment protection are achieved, and installation is convenient.