1. A method for human action recognition, comprising: receiving a plurality of training data, wherein the plurality of training data correspond to a plurality of gestures and a corresponding relationship between the plurality of training data and the plurality of gestures may be one-to-one, or many-to-one; clustering the plurality of training data into at least one group according to a similarity between the plurality of training data; capturing an image sequence of a human action, and obtaining a data representing the human action to be identified from the image sequence; selecting a specific group having a highest similarity with the data to be identified from the at least one group; obtaining a ranking result of all the training data within the specific group through a rank classifier and the data to be identified; obtaining a first training data from the ranking result; and identifying the human action as the gesture represented by the first training data.