The invention discloses a surface morphology measuring device capable of continuous zooming. The device comprises a light source, a collecting lens system, a light splitting prism, an interference object lens, a zooming optical system, an imaging optical system, an area array CCD camera, a micro movement device and an objective table, emergent type of the light collecting system is orientated to the light splitting prism, reflection light of the light splitting prism is orientated to the interference object lens, the zooming optical system is arranged coaxially between the light splitting lens and the imaging optical system, and an interference optical path is integrated and connected with an illumination optical path of the light splitting prism. The zooming optical system is a continuous zooming optical system, and comprises a compensation set, a zooming set and a fixed set. Aimed at requirements of different amplification multiplying power, it is only required to adjust the amplification multiplying power M of the zooming optical system instead of replacing the object lens to zooming in/out the view field of measurement, and the amplification multiple can be adjusted continuously. The device is suitable for realizing the surface morphology measurement in the phase difference interferometry or the vertical white light interferometry.