The invention discloses a dehydrogenation system. The dehydrogenation system comprises a regenerator, a reactor, a catalyst separation device, a heat energy recoverer and a water scrubber. The catalyst separation device is arranged between the reactor and the heat energy recoverer, and comprises a three-level cyclone separator, a three-spin intermediate tank located under the three-level cyclone separator and a waste catalyst tank located under the three-spin intermediate tank. Recycling of the catalyst can be achieved by the dehydrogenation system, the service life of the heat energy recoverer is prolonged, the continuous operation time is long, and the purity of isobutane is high.