Environmental pollution site investigation and risk assessment are particularly important for land security. In order to provide accurate scientific basis for soil remediation and pollution control, a full hydraulic direct push soil sampling drilling rig was developed. The power head of the drilling rig is designed as a multi-functional impact and rotation mechanism, which is more compact than the traditional impact and rotation separation power head. The rack can realize multi-angle tilt operation, the integrated console can realize visual control, and the construction operation is more convenient. The hydraulic system adopts the open load sensing circuit controlled by electro-hydraulic. The rotational speed of the motor and the impact velocity and impact force of the impact hammer can be adjusted in real time with the change of strata and process requirements. The drilling rig has compact structure and visual operation, which is a set of intelligent, modular and lightweight technology integration. It can meet the increasingly stringent technical requirements of domestic soil environmental survey and has broad application prospects.