The present invention discloses a method for preparing stable 3D polymer objects with surface micro-nanostructures. The method includes the following steps: Step (1): Synthesizing a thermoset 2D polymer object with surface microstructures. The polymer network contains reversible exchangeable bonds. Step (2): deforming synthesized polymer to an arbitrary desired shape above the reshaping temperature with an external force applied. The permanent reshaping temperature falls in the range of 50-130° C. and external stress is held for 5 min-24 hours Step (3): after cooling, a permanent 3D polymer object with surface microstructure is obtained. Step (2-3) can be repeated for many cycles and the 2D polymer object can be arbitrarily and cumulatively deformed to get a complex 3D structures. The polymer networks contain reversible exchangeable bonds and bond exchange catalysts in the present invention. The method disclosed in present invention is simple and efficient for preparing complex 3D polymer objects with surface micro-nanostructures.