The invention belongs to the field of steel structure buildings and particularly relates to a manufacturing method of a switching joint with the upper end being round and the lower end being square. The manufacturing method comprises the steps that firstly, a base point is determined, specifically, a moderate-thickness plate is selected, the length of the moderate-thickness plate is one fourth of the cross section perimeter of the switching joint with the upper end being round and the lower end being square, the width of the moderate-thickness plate is the height of the switching joint with the upper end being round and the lower end being square, and the base point is determined on the shorter edge of the moderate-thickness plate; secondly, radial lines are drawn, specifically, after the position of the base point is determined, the base point serves as a base point, and the radial lines are drawn on the shorter edge of the other side of the moderate-thickness plate; thirdly, a heavy-duty press machine is used for pressing; and fourthly, welding is conducted, specifically, the four pressed members with the same specifications are welded together. The switching joint with the upper end being round and the lower end being square is wide in application range and can be used for connecting pieces of the switching joints with the upper ends being round and the lower ends being square of the moderate-thickness plates with different specifications. Labor and resource consuming is less, the manufacturing step is few, the manufacturing period is short, and batched production can be carried out.