Metal coordination crosslinking between stiff N-polyindole chains was constructed, and the crosslinked films exhibited high tensile strength, high heat resistance and excellent polar solvent resistance. The noncovalent crosslinking can be further removed via external pyrophosphate, which endows the crosslinked polymer with a recyclable behavior. The tensile strength and glass transition temperature of the polymers can be nondestructively detected by taking advantage of the fluorescence quenching effect of metal coordination to the adjacent bipyridine structure.