TROLLEY WITH NO HEIGHT INCREASE IN FOLDED STATE

The invention provides a trailer with no extra height when folding, comprising fixed standpipes arranged at a front and rear end of the trailer, and front and rear folding components, side folding components, bottom folding components and handle components connected to the fixed standpipes. The height of the trailer in the invention does not change after folding to ensure that the height after folding and the height in use are the same, thereby the object that the volume after folding is smaller than that of the prior trailer. By proving telescopic components on the handle components, the trailer can be telescopically folded by handle components when not in use, which reduces space occupation and is practical and convenient; simultaneously, by providing reset torsion spring on the handle components, the object of automatically resetting of the handle when the trailer not in use can be achieved.