Abstract: In order to satisfy continuous coal mining requirements of coal-cutter following automation on coal mining face, a laser alignment sensor for alignment of hydraulic supports on working face was designed. Alignment principle based on laser alignment sensor and hardware and software designs were introduced. The sensor uses miniaturization design, and has advantages of easy installation, low price and so on. The results of underground industrial experiments show that average alignment precision of adjacent hydraulic supports can reach 30 mm while applying the sensor to automatic coal mining.