The type of beam-to-column connection in framework structure is determined beforehand in analyzing the frame structure using traditional design method. But it is not comprehensive and exact following that idea. It is difficultly to find the better and more proper design result such as the type of beam-to-column connection and the section of member in many viable design results. Therefore, a new design idea on steel frame -- the active semi-rigid connection design method is advanced in this paper. And some examples on the active semi-rigid connection design and the active semi-rigid connection optimal design are showed. From results, the type of semi-rigid connection makes an important effect on the mechanical behavior of the frame; it will cause the mechanical behavior of the frame to change obviously. And it will be got a better optimal result which considering more comprehensively in the whole frame view based on semi-rigid connection optimal design.