Abstract: Gravitational waves detection can be implemented by probing the modulated phase of the laser beam transporting between the two test masses. To avoid the dual-cavity locking challenge inherent in LIGO-type gravitational-wave detection systems, we proposes a high-sensitivity gravitational wave detection scheme: using a single-link transmitted light beam as the carrier, leveraging the modulation effect of gravitational waves on its phase, and combining Mach-Zehnder interferometry detection technology to achieve high-sensitivity detection of gravitational waves. Based on this scheme, a 10 000 km lunar laser ranging system is designed for the 0.1-10 Hz frequency band, and its achievable gravitational-wave detection sensitivity is evaluated under the limiting noise from laser shot noise and test-mass radiation pressure. This work may provide the useful reference for the construction of an experimental detection system that can achieve the high sensitive detection of gravitational waves in the target frequency band, by just only a high-precision single-link laser ranging system.