The invention discloses a visual and inertial navigation fusion SLAM-based external parameter and time sequence calibration method on a mobile platform. The method comprises an initialization stage, wherein the relative rotation parameters between two frames estimated by a camera and an IMU are aligned through a loosely-coupled method, and the relative rotation parameters of the camera and the IMUare estimated and obtained; a front-end stage, wherein the front end completes the function of a visual odometer, namely, the pose of the current frame of the camera in the world coordinate system isgenerally estimated according to the pose of the camera in the world coordinate system estimated in the former several frames, and the estimated value serves as an initial value of back-end optimization; a back-end stage, wherein some key frames are selected from all the frames, variables to be optimized are set, a uniform objective function is established, and optimization is carried out according to the corresponding constraint conditions, and therefore, accurate external parameters are obtained. By adoption of the method disclosed by the invention, the error of the estimated external parameters is relatively low, and the precision of the time sequence calibration track is high.