The invention relates to a portable electric 
welding machine which solves the problems that a motor-generator welder which is used in existing 
electric power engineering construction causes floating 
voltage between weld handles and threatens personal safety, the motor-generator welder is not in a range of 
visibility of an electric welder, and safety of intermediate links are uncontrollable. The portable electric 
welding machine comprises an outer shell and a rectification and 
filtration module arranged inside the outer shell, a 
battery pack arranged inside the outer shell is used as a direct-current power source, the 
battery pack is connected with a direct / alternating inverting module, the direct / alternating inverting module is connected with the rectification and 
filtration module, the rectification and 
filtration module is connected with an insulated gate bipolar translator (IGBT) power switch element to conduct 
frequency modulation on 
direct current, and the IGBT power switch element is connected with a weld module. The 
battery pack is used as a 
direct current power source, an external power source is not needed, the portable electric 
welding machine can be placed in a safe range of an electric welding position, the length of a 
weld line is quite proper, 
a site of messy weld lines does not occur, dangers are prevented from happening, the portable electric welding machine is located in the range of 
visibility of the electric welder all the time and is in a controllable state, and therefore safety is high.