The invention discloses a down-hole hydraulic power pulse staged fracturing permeability-increasing device and method. The device comprises a down-hole pulse fracturing device, a controllable hydraulic packer, a continuous oil pipe, a fluid control valve and a fracturing truck. The fracturing truck is connected with the controllable hydraulic packer and the down-hole pulse fracturing device through the continuous oil pipe. The controllable hydraulic packer is connected to the back end of the down-hole pulse fracturing device. The fluid control valve is arranged at the connecting opening of the continuous oil pipe. The down-hole pulse fracturing device comprises a first cylinder body, a second cylinder body, a mandrel, a sliding sleeve, a sealing ring, a spring, a nozzle and the like. Under the condition that certain construction parameters such as pumping pressure and displacement are provided for the ground fracturing truck, large-displacement low-frequency pulse fluid is generated at the shaft bottom and is injected in, and a water hammer effect is formed. The down-hole hydraulic power pulse staged fracturing permeability-increasing device is simple in structure, durable and easy to adjust, low-frequency large-displacement pulse energy can be generated, the construction technology is simple, pulse energy can be well used for breaking rocks, net-shaped complex cracks with wide extending ranges are generated, and reservoir stratum permeability is effectively improved.