Geotechnical engineering driller

The invention discloses a geotechnical engineering drilling machine, and relates to the technical field of drilling machine equipment, the geotechnical engineering drilling machine comprises a motor, and one end of the motor is fixedly arranged at the bottom end of a supporting plate; an output shaft of the motor is rotationally connected with one end of the air cylinder; an output shaft of the air cylinder is fixedly connected with the top end of the first drill rod; the second drill rod is slidably connected to the outer side of the first drill rod through a connecting assembly; wherein a mounting plate is fixedly arranged at the top end of the first drill rod, and a cover plate is arranged at the bottom end of the second drill rod; due to the arrangement of the connecting assembly, the mounting plate is fixed to the outer wall of the second drill rod, when the first motor is started, the air cylinder is driven to drive the first drill rod and the second drill rod to slide downwards together, and after prel