An assembly type building peripheral protection device comprises a protection rail vertical rod and a base. Bent steel plates for installing protection wood planks are welded to the protection rail vertical rod, the lower end of the protection rail vertical rod is inserted in a sleeve pipe of the base to be positioned and fixed, and the base is anchored to a pre-buried sleeve on the side face of the top of an external wall plate. An elastic piece is installed at the lower end of the protection rail vertical rod, a pin piece is fixed to the elastic piece and corresponds to the elastic piece, and a pin piece pop out groove is formed in the wall of the sleeve pipe of the base. The assembly type building peripheral protection device is simple and handy in structure, easy to assemble and disassemble, low in cost, capable of being repeatedly used and effectively preventing objects from falling from high altitudes and casualties, and good in safety performance.