Foot pedal operated spot welding machine adopts lever pedal type spring pressurized structure. Easy operation, quick response. Suitable for various kind of positioning accuracy and complicated shape welding occasion. Under the operation of transformer, foot pedal spot welding machine utilizes the general mains supply to lower the voltage and increase the electric current. Such kind of low voltage but large current will be transmitted from the electrode to the linked point of two work pieces. On the linkage, due to the resistance of work piece, high temperature will occur so the metal will therefore generate high heat to make the work pieces in the molten condition. Thus, the purpose of welding the two pieces of work pieces is achieved.