The invention discloses a welding method of a multifunctional hot pressure welding machine. The method comprises following steps: firstly, a circuit board to be welded is placed on a work table of a base surface, and through a positioning block on the work table, determining of the designated welding wire position is carried out; a power source of the hot pressure welding machine is turned on, and through a control keyboard on a control panel on the surface of a control host, a hydraulic drive box is controlled to drive a lifting rod to move downwards. The welding method of the multifunctional hot pressure welding machine has the beneficial effects that a temperature feedback control loop composed of a temperature detector, the control host and a heater can automatically control the pressure head to be heated to the reserved temperature value, the circuit board damage caused by the too high pressure head temperature and the influence of the too low temperature on the welding effect are avoided, and the good manufacturability of the hot pressure welding machine is ensured, and practicability is good.