According to the stealth characteristics of stealth aircraft, a laser fence technology, as a new target detection method, using distributed laser active scanning and laser echo receiving to perform warning detection is proposed. The principles of laser fence technology and the composition of transmitting and receiving sub-system are introduced. According to flight parameters of typical stealth aircraft in foreign countries, 17.3 km interval is used to design laser transmitting and receiving devices to design the parameters of the transmitting sub-system in the laser, such as laser optical beam scanning angle, repetition rate, pulse width, 3.2 mJ single pulse energy and average power. The calculation results show that the method can meet the detection demand of a stealth aircraft with 15 km flight altitude and 1.5 Ma flight speed.