Semi-dry method plasma-FCAW underwater hybrid welding device

The utility model discloses a semi-dry method plasma-FCAW underwater hybrid welding device which comprises an FCAW system and a plasma system, a plasma-FCAW hybrid welding method is applied to carry out underwater welding, a workpiece is preheated by utilizing the characteristic of high plasma arc energy density, and the cooling rate of the workpiece is reduced; the welding penetration depth is increased or decreased through the deep penetration effect of the plasma arc, and the welding efficiency is improved; real-time changes of FCAW current are collected through a Hall sensor, longitudinal mechanical movement of a magnetic pole end is controlled according to the changes of the current so as to change the magnetic field intensity of an electric arc area, and then the acting position of a plasma electric arc and an FCAW electric arc and the welding process are controlled. Through effective combination of plasma and FCAW electric arc, the welding efficiency can be remarkably improved on the premise that the q