The invention relates to a four-axial four-subdivision interferometer. The interferometer comprises a four-axial light splitting module and an interference module, wherein the four-axial light splitting module and the interference module are successively arranged along a polarized quadrature double-frequency laser incident direction. The four-axial light splitting module is composed of three plane spectroscopes and three 45-degree total reflective mirrors, wherein a splitting ratio of each the plane spectroscope is 50%. The interferometer provided in the invention comprises a four-axial four-subdivision plane mirror interferometer and a four-axial four-subdivision difference interferometer; in the difference interferometer, adjustable 45-degree reflector is employed to guide a reference light to a reference reflector that is placed at the same direction as a measuring mirror and is fixed on a moving object. According to t the invention, the interferometer has the following advantages that: the element is easy to be processed; an optical path adjustment is convenient; a temperature drift is small; temperature drifts of light beams of all paths are consistent; a non-linear error is low; and an optical efficiency is high.