The invention is related to an automatic dice-throwing method and its device. The method is mainly to achieve dice throwing by an automatic device, which consists of; driving the dice container (60) to rotate 180 degrees, driving the arm (90) to capture the dice, driving the dice container (60) to rotate and return and riving the arm (90) to return and throw the dice; the device has a large driving motor (30) to control the rotation and return of the dice container and uses a small driving motor (80) to control the swinging and return of an arm (90); to facilitate the operation a controller (100) is installed, to facilitate getting the result a small camera (701) records the process and a display (110) shows the points.