The invention relates to a coaxial digital holographic measuring device for a transparent substance based on the beam-splitting property of a Fresnel biprism. The measuring device consists of a laser, a beam expander, a transparent object to be measured, a Fresnel biprism, a CCD (charge coupled device) camera and the like. In the invention, after light sent by the laser is expanded, one part of the light is projected on the Fresnel biprism through the object to be measured and then is split into two beams which form an included angle, and interference information between the two beams is recorded by the CCD camera; and meanwhile one coherent beam of the two beams passes through the object to be measured, thus forming a hologram carried with object information. The device has the advantages of fewer components, simple structure and good portability; and the recording device can be applied to testing structural and state parameters of the transparent substances such as a transparent medium, a living cell and the like.