Disclosed are a gesture detection and recognition method and system. The gesture detection and recognition method comprises: acquiring and storing an image; adopting a plurality of pre-set classifiers for deleting different gestures to detect each frame of the image according to a pre-set sequence in a frame alternating manner to acquire a gesture target; establishing a skin color model based on the pixel distribution of the region of the gesture target; and acquiring gesture frequencies of the gesture target in a previous state and a later state according to the skin color model, and matching the gesture frequencies with a pre-set gesture state, so that a gesture change state is obtained and output. The gesture detection and recognition method and extract a skin color under specific scene, and can gradually eliminate the influence generated by acute illumination changes, thus realizing the purpose of extracting a gesture change state.