Thermoregulated phase-separable Rh nanoparticles (abbreviated as TPS-Rh_nano) were found to be efficient catalysts for selective hydrogenation of CC bonds in α,β-unsaturated aldehydes and ketones with a selectivity of >99% at >99% conversion. More importantly, the catalyst could be easily separated by simple phase separation and reused directly eight times without evident loss in activity and selectivity.