The key technologies of physical simulation experiment system for tunnel engineering are comparatively analyzed by summary and classification; and the stateofart and development trend of the abovementioned system are presented systematically. And then a new classification method for experiment system is proposed based on model size. The analytical results show that: 1) The small and mediumsized experiment system is advantaged in low cost, rapid model establishment, accurate loading control, fine deformation measurement and high efficiency and good economic benefit, which can be a main alternative scheme for construction of physical simulation experiment system for tunnel. 2) The physical experiment technologies of digital photogrammetry and 3D printing would be a new development direction in the future.