The utility model discloses a key drilling action single-pump hydraulic control loop of a cutting drilling machine, which comprises a load sensitive variable pump, a load sensitive multiway valve, a rotary motor, a thrust cylinder, a drilling logic control block, a rotary pilot handle, a thrust pilot handle and a hydraulic oil tank, wherein an oil inlet of the load sensitive variable pump is connected with a hydraulic oil tank, an oil outlet and a load sensitive port of the load sensitive variable pump are respectively connected with an oil inlet and a load sensitive port of the load sensitive multway valve, each valve pressure difference compensator of the load sensitive multiway valve is provided with a load sensitive external control port, the external control port of each pressure difference compensator is connected with the drilling logic control block, and pilot control ports of the rotary pilot handle, the thrust pilot handle and the drilling logic control block or load sensitive multiway valve are connected. The utility model realizes functions of power head rotary proportion control propulsion, high speed rotation and propulsion superior to rotation, rapid rod lifting, maintaining of a certain rotary speed, and the like.