An exposure compensating method applied to a camera apparatus includes acquiring a monitoring image captured by the camera apparatus via an exposure parameter, computing an estimating exposure compensating value of the monitoring image according to a triggering threshold, analyzing continuity in pixels of the monitoring image with intensity conforming to a specific condition to acquire a weighting adjustment value of a region of interest, adjusting the estimating exposure compensating value via the weighting adjustment value to generate a final exposure compensating value, and adjusting the exposure parameter by the final exposure compensating value.