The invention relates to the technical field of floating machines, in particular to a full automatic dip soldering machine which comprises a machine body. An atomizing device, a preheating device, an automatic lifting tin furnace, an angle deflection device and a printed circuit board (PCB) conveying line are installed in the machine body. A chain wheel is installed on a main beam on the PCB conveying line, and a hinge, a chain connector and a transmission assembly are installed on the main beam. When tin feeding operation is conducted, a PCB can enter a floating machine automatically to achieve angle soldering in a tin soldering area and automatically flow to the next procedure after soldering. Therefore, the full automatic dip soldering machine is simple in operation, has advantages of being high in yield, low in cost and the like and is applicable to dip soldering operation. Product quality can be well guaranteed due to automatic control.