The utility model relates to an assembled steel guardrail for protection of high mound construction platform can fast assembly and dismantlement, improves labor efficiency greatly, saves the engineering time, and simple structure, practices thrift the cost. The scheme is, including the staple bolt base, staple bolt base suit is at high mound construction platform's I -steel beam end, fixedly connected with rail stand on the staple bolt base, the rail horizontal pole of three perpendicular to I -steel crossbeam and stand is passed at the vertical interval of rail stand, both ends are equipped with the inside through -hole of break -over around the staple bolt base upper portion, and there is the fixation nut of welding on the staple bolt base on through -hole upper portion, and the fixation nut top spin is twisted has the lock solid bolt that passes the through -hole, be fixed with safety protection net on the rail horizontal pole. The utility model discloses simple structure, manifold cycles utilizes energy -concerving and environment -protectively, and the installation is dismantled very conveniently, saves artifically and the engineering time and the used equipment of being under construction, can improve the security performance and reduce safe risk coefficient.