A device for measuring length and center of mass of conical workpiece, including an inner frame, an outer frame, a base plate, two laser displacement sensors and a plurality of weighing mechanisms. The inner frame is rotatably connected with the outer frame through a pin shaft. A bottom surface of the conical workpiece can be fixedly connected with an inner bottom surface of the inner frame. The base plate is removably arranged on the inner frame, and abuts against a top of the conical workpiece. The base plate is perpendicular to an axis of the conical workpiece. The laser displacement sensors are fixedly arranged at a position of the inner frame below the top of the conical workpiece. The weighing mechanisms are provided at a bottom of the outer frame, and can bear the inner frame, the outer frame and the conical workpiece.