The invention relates to a spatial carrier based interference confocal measuring device and a method, belonging to the technical filed of measurement of surface topography. The measuring device comprises a laser, a collimation focusing objective lens, a pinhole, a collimation expander objective lens, a polarization beam splitter, a quarter wave plate, a beam splitter, a detection focusing objective lens, a second microdrive and a collecting objective lens, wherein the rear side of the beam splitter along the direction of a primary optical axis of the laser is sequentially provided with an auxiliary reference lens and a first microdrive, a main reference lens is arranged between the beam splitter and the detection focusing objective lens, a CCD camera is placed on a focus position of the collecting objective lens, and a master control computer is connected with the CCD camera and the first microdrive. The method comprises the steps: establishing displacement and phase relation by a secondary confocal method, introducing a carrier signal by tilting the auxiliary reference lens, obtaining a carrier interferogram, acquiring the phase information of a measured surface by a spatial carrier phase-shifting algorithm, and finally fitting surface topography and three-dimensional profile. The invention is suitable for dynamic, quick and high-precision measurement of micro-structure three-dimensional topography.