Abstract: To avoid the dual-cavity locking challenge inherent in LIGO-type gravitational-wave detection systems, a high-sensitivity gravitational wave detection scheme was proposed. A single-link transmitted optical beam was used as a carrier, and the gravitational-wave-induced phase modulation on the beam was sensed and, in combination with Mach-Zehnder interferometry, was utilized to achieve high-sensitivity gravitational wave detection. A 10 000 km lunar laser ranging system was designed for the 0.1–10 Hz frequency band, and its achievable gravitational-wave detection sensitivity was evaluated under noise limitations from laser shot noise and test-mass radiation pressure noise. This study provides a reference for the development of a laser ranging-based experimental system aimed at high-sensitivity gravitational wave detection in the target frequency band.