The invention discloses a multifunction three-dimensional displacement and 
topography laser interferometry system, belonging to the technical fields of photo 
mechanics, 
engineering material, structural member deformation, displacement testing, 
topography measurement and the like. The invention consists of a 
laser device, a image collecting and shooting 
system, a light split coupler, a light split 
photoswitch, a DC electrical source controller, a three-dimensional 
laser interference 
optical path system, a loading charging floor for putting test pieces, a bracket adjusting system, a computer and the like. The 
laser interferometry system can realize high-precision measurement of u, v and w displacement fields, and displacement measurement sensitivity can reach 
wavelength magnitude; the 
laser interferometry system has two displacement measurement 
modes of 
digital holography and electronic 
speckle pattern interferometry, and also has the mode of digital holographic measurement of surface 
topography. The invention can realize the adjustment of 
degrees of freedom on multiple directions by using the bracket adjusting system, brings convenience for system imaging and measurement adjustment, and has the characteristics of convenient use, compact structure, high 
measurement precision and the like; because the system is provided with a phase shifting device, the displacement 
measurement precision of the system of the invention can reach nanometer magnitude after phase shifting treatment.