The utility model is suitable for a building technical field provides a connected node of steel construction, including upper portion node and lower part node, the upper portion node is cylindricly, and the lower part node is hemispherical shape, and the top of lower part node is plane, the top of lower part node and the bottom surface fixed connection of upper portion node. The utility model discloses a connected node can pass through on a node with the circular shape member square mutually to, the spatial distribution direction of each member is different, and the axis of each member does not hand over in a bit, has avoided the complicated of node atress way, can reduce the stress concentration problem among node equipment simultaneously, the welding process. Increase the area of contact between member and node, avoided alternately welding seam, done benefit to the joint strength who increases between member and the node. There is not the restriction of passing through the order mutually between each member in this node structure when assembling with the member, the equipment and the welding of each member do not influence each other, greatly reduced the node processing preparation degree of difficulty.