In this paper a description of the first SPG-1 model digital wavefront interferometer for scientific research in P.R. China, designed and made in our university in 1985, and two other new models of digital interferometer (SPG-II and CQG-I model) designed and produced for shop testing are described. These instruments are based on a technique with Fourier phase interferometry. The combination of laser technique with interferometry and microcomputer techniques makes it the most accurate, powerful, and efficient interferometric instrument at present. It is mainly used for measuring of figure of optical surfaces (flat, aspheric surfaces and prism surfaces), uniformity of transparent materials, and quality of gratings. When proper additional accessories are used it can also be used for quality appreciation of aspherical surfaces and various kinds of lenses. A microcomputer (IBM-PC/XT) is used for data sampling and data processing. Phase resolution of (lambda) /1000 ((lambda) equals 632.8 nm) and accuracy of surface figure (lambda) /40 are obtained. The instrument can show real-time 3-D display, contour map, and the values of PV, RMS, and PTS, and typewrite all the fringe data. Owing to the powerful software package, it is easy to operate. The simple optical system keeps the cost of this instrument lower.