A fiber-space hybrid optical path interferometer is constructed. The geometrical form of the shape

of interference fringes in space is derived from assuming the point source of optical fiber emission and verified experimentally. The parameter model of the interference intensity is established，and the fringe visibility and polarization characteristics of the interferometer are discussed. Theoretical，experimental and parametric application model show that the interferometers are characterized by miniaturization，visualization and ease of operation. They can be used to general-|purpose interferometers for fringe phase shift detection，shear interference measurement and optical holography，and can also be used to expand the optical fiber sensing functions.