The disclosure relates to an APS based integrated sun sensor comprising: a diaphragm unit, a detection unit, a processing electronics unit and an interface unit. The diaphragm unit is operatively connected with the detection unit for forming a sunspots image. The detection unit is configured for outputting a gray value of each pixel. The processing electronics unit is operatively connected with the detector unit and the interface unit respectively, for evaluating an attitude angle on the basis of the gray value and coordinate of each pixel. The interface unit is operatively connected with a host computer, for transferring the attitude angle to the host computer. This disclosure has such merits as high accuracy, wide FOV (Field of View), low power consumption, low weight, small size and high update rate.