The utility model relates to the technical field of oil field borehole operation, in particular to a box type skid-mounted variable frequency electric well testing winch. The winch is design into a sealed box, an upper cover of the box can be opened, all side surfaces of the box are provided with box doors provided with built-in locks, fork openings are arranged at the bottom of the box, universal wheels are installed at the bottom of the box, lifting hooks are installed on four corners of the upper portion of the box, and a frequency modulator connected with a turbine reducer through a motor is added on the winch. According to the box type skid-mounted variable frequency electric well testing winch, the box type skid-mounted structure is reasonable and compact, devices are convenient to move, transport through forking or hoisting is facilitated, and a power gear shift mechanism can achieve stepless speed regulation, and the reliability is high; and defects that the existing winches are complex in structure, small in speed regulation range of drums and high in investment are overcome.