Gravitational waves (GWs) are ripples in space-time generated by massive accelerating objects. Although Einstein predicted the gravitational waves in 1916, the first direct demonstration of their existence didn’tarrive until 2016, 100 years after his prediction. Since then, over 90 gravitational wave events have been detected, including binary black hole mergers, binary neutron star mergers, neutron star and black hole coalescences. The direct detection of gravitational wave has revolutionized humanity’s view of the universe, and opened a new era of gravitational wave astronomy. The operational second-generation (2G) ground-based gravitational wave detectors include two LIGOs in Hanford and Livingston in the United States, Virgo in Italy and KAGRA in Japan. However, the strain sensitivity of the second-generation gravitational wave detectors is not enough to detect the majority of stellar-mass black hole and neutron star coalescences in the universe. This problem can be addressed by the third generation (3G) gravitational wave observatory whose strain sensitivity (10-24Hz-1/2) is ten times that of the 2G gravitational wave detectors. Based on the low-noise laser source from Shanxi University and abandoned coal mines in Shanxi, the provincial government has approved to build a third-generation ground-based gravitational wave detector, naming “Diting”. To date, all the operational ground-based gravitational wave detectors are based on large scale Michelson interferometer with arm length of several kilometers. In this paper, we calculated the frequency responses of the Michelson interferometer, the Fabry-Perot Michelson interferometer and the power-recycled Fabry-Perot interferometer respectively. To meet the strain sensitivity of 10-24Hz-1/2, we determine the amplitude reflectivity of Fabry-Perot cavity and the power-recycled mirror. Thispaper paves the way to build a third-generation ground-based gravitational wave detector in China.