The present invention discloses a method and apparatus for changing lip shape and obtaining a lip animation in a voice-driven animation, and relate to computer technologies. The method for changing lip shape includes: obtaining audio signals and obtaining motion extent proportion of lip shape according to characteristics of the audio signals; obtaining an original lip shape model inputted by a user and generating a motion extent value of the lip shape according to the original lip shape model and the obtained motion extent proportion of the lip shape; generating a lip shape grid model set according to the obtained motion extent value of the lip shape and a preconfigured lip pronunciation model library. The method for changing lip shape in a voice-driven animation includes an obtaining module, a first generating module and a second generating module. The solutions provided by the present invention have a simple algorithm and low cost.