1. A method for automatically selecting a scene mode applied in a photographic device, comprising: providing a plurality of scene modes, each corresponding to a utilization rate, at least one feature standard, and a set of photographic parameters; detecting an image to be captured; analyzing the detected image to acquire at least one principal feature of the image; comparing the principal feature with the feature standard of each scene mode according to a comparison sequence of utilization rate ranging from high to low, so as to acquire the scene mode corresponding to the feature standard conforming to the principal feature; and adjusting the current photographic parameters of the photographic device into photographic parameters corresponding to the acquired scene mode.