The application relates to the technical field, and discloses a
metal pipeline
welding device for municipal construction, which comprises a
welding seat, two semicircular steel rails arranged on the two sides of the
welding seat, a
power component fixed on the welding seat, a functional groove arranged on the welding seat, a
stroke sliding frame fixed in the functional groove, a displacement plate slidingly arranged on the
stroke sliding frame, a thermal drive component fixed in the functional groove and the displacement plate, and a heat dissipation component fixed on the welding seat. The control panel of the application adjusts the output current of a welding battery, the current is transmitted to a nitinol wire through a positive
electrode connecting rod, a negative
electrode connecting rod and a
metal joint, the nitinol wire is heated, the shortening amount of the nitinol wire is accurately controlled according to the current size, the current
temperature control expansion and contraction characteristics of the nitinol wire are combined with the linear transmission of the displacement plate and the accurate angle conversion of the angle adjusting gear,
millimeter-level fine adjustment of a
welding joint is realized, the irregular welding gap can be efficiently adapted, and welding defects can be avoided.