The utility model relates to a corner brace structure in deep basal pit assembled combination steel construction, include: slant steel shotcrete, slant are propped up and are located the steel enclosing purlin who is located foundation ditch bight department, the slant steel shotcrete including the slant I -steel that is located tip department and with slant I -steel fixed connection's support steel pipe, and build in in an interior force transmission component of support steel pipe, just a force transmission component 's tip with the corresponding setting of slant I -steel and with the slant I -steel is connected, thereby passes through a force transmission component will the direct transmission that corresponds of the support pressure that the steel pipe transmitted extremely the slant I -steel. The 3rd force transmission component of cause corresponds with the cross -section of slant I -steel for the whole direct transmission of power of supporting the steel pipe transmission are transmitted for steel enclosing purlin via the slant I -steel to the slant I -steel again, have realized the better transmission of doing all can, have improved the ultimate bearing capacity of node.