The invention discloses an automatic program controlled medicine weighing device, which comprises a rack, a fixing plate, a medicine storage device, a vibration conveying device, a sensor base, weighing sensors, a weighing bucket and a tray, wherein the vibration conveying device is connected with two spring plates; the number of the weighing sensors is the same as that of medicine conveying slots; one side of the fixing plate is fixedly connected with a stepping motor, both upper and lower ends of the other side of the fixing plate are provided with a linear bearing cover, the top end of a linear bearing is fixedly connected with the sensor base, the middle part of the linear bearing is provided with a rack which corresponds to a motor gear in position and meshed with the motor gear, thefront end of a gravity sensor is fixedly connected with the tray, and the rear end of the gravity sensor is connected with the sensor base. The automatic program controlled medicine weighing device iscontrolled by a mechanical automation program and accurate in weighing, saves the to-and-fro process in medicine weighing, saves the labor, improves the efficiency and can be widely applied to the metering production process of medicine and hazardous material industries.