The invention discloses a mechanical power head long stroke feeding mechanism and an operation method thereof. The mechanical power head long stroke feeding mechanism comprises a drilling rig rack, amotor, a clutch, a gearbox, an oil pump, a winch, a water brake device, a winch rack, a sleeve roller chain, a hexagonal vertical shaft, a drill rod, a hydraulic chuck, a power head, an arc tooth box,a first universal coupling, a first pneumatic clutch, a transfer case, a second pneumatic clutch and a second universal coupling. The invention further discloses the operation method for the mechanical power head long stroke feeding mechanism. For the mechanical power head long stroke feeding mechanism disclosed by the invention, by adopting the mechanical power head, the power transmission efficiency is high with high efficiency and energy conservation; by adopting a mechanical power head double-oil cylinder long stroke feeding device, a feeding stroke reaches 3.33 meters, and a core can betaken after primary feeding; and a power head sliding frame adopts a rolling wheel structure, and sliding friction is changed into rolling friction, so that rail abrasion is reduced, the running resistance is lowered, and in addition, maintenance and replacement are facilitated.