High stable common-path digital holographic interferometers can be widely applied in long-term time-lapsing interferometric measurements, three-dimensional imaging, and quantitative phase imaging. Scientists in China reviewed the common-path off-axis digital holography and categorized the common-path models into lateral shearing, point diffraction and other types, and summarized the progress of this topic in detail. Benefiting from compact features, common-path digital holography is very promising for the manufacture of highly-stable optical measurement and imaging instruments in the future.