Folding mechanism applied to smoke tube decorative cylinder of range hood

The folding mechanism comprises a liftable front wall plate assembly, liftable corner connecting plate assemblies capable of moving left and right are arranged on the two sides of the liftable front wall plate assembly respectively, and liftable side wall plate assemblies capable of moving front and back are arranged on the outer sides of the liftable corner connecting plate assemblies. Height keeping structures for keeping the same height are arranged among the liftable front wall plate assembly, the liftable corner connecting plate assembly and the liftable side wall plate assembly, the proportion of the length, the width and the height of a front wall plate and a side wall plate of the decoration barrel can be controlled to be adjusted, and adjustment is more convenient; the length, width and height of the decorative cylinder can be folded, so that the occupied volume of the decorative cylinder is minimized, and the decorative cylinder is convenient to transport; smoke exhaust pipes with different sizes ca