Portable damping-adjustable lowering cable measuring device

The utility model belongs to the technical field of water conservancy monitoring, and relates to a portable damping-adjustable lowered cable measuring device which comprises a pay-off rack, a U-shaped damping pay-off device, a first roller, a second roller, a third roller, a sensor and a cable. A cable passes through a threading hole of the U-shaped damping pay-off device, then sequentially bypasses the upper end of the first roller, the lower end of the second roller and the upper end of the third roller and then enters the monitoring well; the sensor is fixedly connected with the tail end of the cable in the monitoring well; according to the utility model, the frictional damping of the cable can be adjusted at any time, so that the speed of the cable falling into a well can be adjusted in real time, and therefore, single-person operation descending, single-person field installation, paying-off and maintenance can be realized when the super-long cable falls into the well, the labor cost is greatly reduced, a