The invention relates to a device and method for collecting water samples and measuring hydrological parameters in a fixed-point section of a water exploration and drainage hole. The device comprisesan early-stage packing device, a water inlet pipe, a tail-end packing device, an extension pipe and an aperture measuring device, wherein the early-stage packing device cuts off the water flow comingfrom the front end of a drilled hole, the water inlet pipe ensures the water flow in a measurement section to flow into a measurement steel pipe, the tail-end packing device blocks the runoff of the water flow in the measurement section, the extension pipe puts the early-stage packing device, the water inlet pipe and the tail-end packing device into designated positions and leads the water flow inthe measurement section into the aperture measurement device, and the aperture measurement device completes water sample collection and measurement for the water temperature, water pressure and waterinflow. Meanwhile, the invention further discloses an application method of the device. The device and method disclosed by the invention realize water sample collection and measurement for the outletwater amount, the water temperature and the water pressure for different sections of the water exploration and drainage hole. The device has the advantages of good sealing performance, simple structure, ability of repeated usage, convenient operation and the like.