The utility model relates to an adjustable clamp of a displacement sensor, which at least comprises a positioning device, a height adjusting device and a clamping device, wherein the positioning device is mounted on an upper test platform, and a measuring rod of the displacement sensor can be ensured to point to the displacement change direction of a measured point through the adjustment of the positioning device; a mounting hole for the height adjusting device is formed on the positioning device, and the height adjusting device is connected with the positioning device through the mounting hole for the height adjusting device; the clamping device is connected to the lower bottom of the height adjusting device, the displacement sensor is clamped on the clamping device, and the measuring rod of the displacement sensor can point to the displacement change direction of the measured point. The adjustable clamp can quickly, conveniently and accurately adjust the height of the displacement sensor, simultaneously ensure that the measuring rod of the displacement sensor points to the displacement change direction of the measured point, not only consume less time and realize high measurement efficiency, but also reduce the human error and improve the measurement precision.