The jet-pan is a key part of jet-pan servo valve. Required precision of jet-pan should be guaranteed in process. CCD microscope measurement is used to deals with the measurement of jet-pan in the paper. The worepiece is enlarged by the optical microscope, and a series of image processing algorithms is used to process the image. The basic dimensions and geometrical tolerance of jet-pan are measured. And the stability error is less than ±0.5μm.