Truss systemThe truss system consists of top strip truss, ring truss and inner strip truss. The top of the top strip truss is connected with the vertical lifting system, and the bottom is used to lift the lower ring truss, whose length shall meet the requirements of the lifting point range of the steel beam at the top of the venue and the width of the ring truss; The top of the ring truss is set up guide rails, and the inner strip truss can move along the guide rails within the scope of its ring internal space; the inner strip truss is slightly lower than the ring truss, The guide rail slider is installed at the top of the inner strip truss to connect it with the top guide rail of the ring truss, and the bottom guide rail is set in its length direction (i.e. the top and bottom of the inner ring truss are provided with double-layer guide rails which are perpendicular to each other). The bottom guide rail is connected with the camera system, and the camera system can move along the bottom guide rail as well as the top guide rail together with the inner strip truss.