The utility model provides a binding post used for a DC-DC converter. One end of the binding post connects with a printed circuit board of the DC-DC converter while the other end of the binding post connects with a client-side circuit board. The binding post includes an electrically conductive connection component and a supporting component. The electrically conductive connection component goes through the supporting component. The supporting component is made of electrically conductive material. At least one gap is arranged in a connection end of the supporting component and the client-side circuit board to let gas flow out. By using the technical scheme provided in the utility model, the gas generated in welding can be discharged, the defect welding is avoided, and the immobility of the connection of the binding post and the client-side circuit board can be improved further.