Abstract: The present disclosure providing a geological sampling backpack drilling machine includes a housing, a drilling device movably received in the housing, a seat arranged on the housing, and a bracket detachably connected to the housing via a limiting rotator, with an angle between the bracket and the housing being variable; the seat arranged between a tip of a drilling rod and the bracket, and rotating around the drilling rod as an axis thereof; a rotating member arranged on a surface of the seat and surrounding around the drilling rod to detachably connect with a supporting post, both the supporting post and the bracket cooperatively supporting the drilling device; the drilling rod passing through the housing and the seat; both the bracket and the supporting post supporting the drilling device that is obliquely drilled and the housing for enabling the drilling device to stably drill at an inclined state.