The invention relates to a static walk gait and diagonal trot gait switching algorithm applied to a quadruped bionic robot, and provides six conditions in which an intermittent static walk gait is switched to a diagonal trot gait, and an optimal switching method. According to the algorithm, a defining method for describing the positions of foot ends in a gait switching process is given, and the intermittent static gait and points, which can be switched, thereof as well as the diagonal trot gait and points, which can be accessed, thereof are provided; after that, rules of rhythm control and a strategy of mode control are given in the gait switching process, so that the smoothness of speed is guaranteed in the switching process; finally, an improved generic stability margin stability discrimination method is provided, so that the stability of a robot body which is in a state of acceleration can be accurately monitored during gait transition. The algorithm considers phase difference and switching speed at the same time, thus shortening the time difference from receiving a switching signal to beginning the switching while improving the stability and smoothness of gait switching, and enabling the gait switching of the robot to be stable and efficient.