The invention discloses a step triangular bracket component detection tool which comprises a worktable, a triangular bracket and two detecting devices. The worktable is provided with a main shaft basefixing block for detecting the main shaft base of the triangle bracket. An auxiliary shaft base fixing block is used for detecting the auxiliary shaft base of the triangle bracket. In the two detecting devices, air cylinders are connected with angled member push blocks which are connected with angled member push heads. Thus, two devices for detecting an upper angled member and a lower angled member are formed respectively. The detection tool can accurately detect whether the triangular bracket member is installed in accordance with a standard and avoids installation incapability in a step assembly process, greatly improve detection efficiency, does not use measuring tools, avoids the uncertainty caused by manual detection, is simple in operation, can reduce labor cost.