The invention relates to a well drilling machine, in particular to a plugging-assembly type well drilling machine comprising a frame made of channel steels and / or angle iron, a power source, a gearbox, a hoist, a rotary machine head, a tower and a main drilling rod which is located in the rotary machine head. The power source, the gearbox, the hoist, the rotary machine head and the tower are fixed to the frame; a suspending pull rope is wound on a hoisting drum of the hoist, one end of the suspending pull rope penetrates a guide wheel of the tower to fix to an elevator, the elevator is connected to an elevating head, and a tap is fixed below the elevating head. The power source, the hoist, the gearbox and the rotary machine head are fixed to the frame through a plugging type connecting frame and a locking limit device. Thus, the plugging-assembly type well drilling machine has the advantages that structure is simple, disassembling is facilitated, transportation is benefited, well drilling efficiency is improved, one single well drilling machine is light, work intensity is reduced, and wells can be drilled without geographical restrictions.