The invention discloses an octave type short coherence transient phase-shifting interferometer and a measurement method used for detecting spherical topographic characteristics and relates to the technical field of optical detection. The problems that a traditional time domain phase-shifting interference measurement device is narrow in detection range and low in measurement precision and is influenced by environmental factors are solved. The interferometer comprises a short coherence laser, a spatial filter, a beam splitter prism, an optical fiber coupling mirror, a polarization splitting prism, a lambda/4 wave plate, a 4f beam-expanding system, a micro objective, a plane mirror, a single mode optical fiber, an optical fiber collimating lens, a corner cube mirror, a cube-corner prism, a lambda/2 wave plate, a polarization splitting prism, a first parallel beam splitter, a second parallel beam splitter, a wave plate group, a polarizing film, an area array charge coupled device (CCD) and a computer. A positioning relationship among four interference images is obtained through four interference patterns of the area array CCD through the computer, so that the initial phase difference which corresponds to each pixel point in an interference field is solved, the optical path difference is further solved, and the spherical morphology is measured. The interferometer is suitable for detection of spherical topographic characteristics.