Vibrating screen is driven by double vibrating motor. When the two vibrating motors synchronize and rotate backwards, the excitation force produced by the eccentric block counteracts each other in the direction parallel to the motor axis and overlaps into a resultant force in the direction perpendicular to the motor axis, so the motion track of the screen machine is a straight line. The shafts of the two motors has a tilting angle relative to the screen surface. Under the resultant force of excitation force and material self-weight force, the material is thrown and jumped forward to make a straight line motion on the screen surface, so as to achieve the purpose of screening and grading the material.