Abstract: This invention is concerned with an improved structure for the conventional vibro separator which features:A. A novel sereen assembly structure: An additional coarse screen (2-16 mesh) is employed for supporting purpose. It will be secured on a special designed screen frame in order to keep the screen surface in a flat manner. And then the main screen (fine mesh) can be put flatly on coarse screen. It is to be fastened by folding and pressing tight the outside edge into the position between the flanges of spacing frames without using any bolt on welding.B. A new designed ball tray assembly: A certain number of plastic rings are freely added in the ball tray as barriers to confine the tapping balls into certain groups in order to even distribute the tapping balls. And a simplified structure for ball tray assembling is designed with only putting the tray on the flange of lower spacing frame and to be held in position by the inner shoulder cutting space at the bottom of screen frame.C.