In order to ensure flight safety and to improve the capability of the airport runway as far as possible, an aircraft wake vortex coherent laser detection system is designed. Begin with the requirements of wake vortex laser detection, the structure of the system is proposed. The parameters of the laser source and the optical path of the double balance detection are designed at the same time. The performance simulation proves that this detection system can meet the detection requirements. When the output energy is higher than 25 mJ, the detection signal-to-noise-ratio (SNR) can be up to 3 dB at the distance of 7 km and the detection accuracy is better than 0.2 m/s within 2 km.