Abstract: A hydraulic support height measueement sensor based on Pascal's law is designed to address the difficulties in measuring the height, reliability, and stability of hydraulic supports in fully mechanized working faces. The height measurement sensor is equipped with a slender liquid tube, which is filled with methyl silicone oil. Pressure sensors are installed at both ends of the height measuremenr sensor. By measuring the pressure at both ends of the sealed liquid tube, the height difference between the two ends of the height measuremenr sensor is obtained. Methyl silicone oil has obvious thermal expansion and contraction characteristics when the ambient temperature changes, which can cause a sharp change in pressure in a closed space and affect measurement precision. A compensation method is proposed. The method stores a portion of methyl silicone oil in a corrugated tube, and uses the elasticity of the corrugated tube itself to compensate for the volume change caused by thermal expansion and contraction of methyl silicone oil. The method calibrates the density change caused by the volume change of methyl silicone oil through algorithms in the software to ensure the measurement precision of the height measurement sensor. The test results show that the height measuremenr sensor can operate in an environment of 0-40 ℃, with a measurement error of less than 4 cm. The on-site application results of the hydraulic support in the fully mechanized working face of thin and medium thick coal seams show that compared with manual measurement results, the error of the height measurement sensor is within 5 cm, indicating high reliability of the sensor.