Inter-satellite laser interferometry is an advanced technique for high-precision measurements in space. In this work we discuss a ground experimental demonstration of transponder type intersatellite laser interferometry. The digital phase-locked loop (DPLL) architecture is used to accurately maintain a 10 MHz frequency difference in the heterodyne interferometer. The displacement measurement accuracy of the interferometer is better than \(\mathrm {10 \ nm/\sqrt{Hz}}\) at \( \mathrm {0.1 \ Hz}\) , and the Angle measurement accuracy is better than \( \mathrm {0.3 \ \mu rad/\sqrt{Hz}} \) at \( \mathrm { 0.1 \ Hz }\) , after the performance optimization. This research provides fundamental data and technical support for further improving the accuracy of optical interferometry.