The invention relates to a detachable micro-channel reactor which comprises a housing and a partition plate, wherein the housing is an internally-grooved structure, and the partition plate is inserted into a channel of the housing; when only one partition plate is arranged, a micro-channel required by chemical reaction is formed between the partition plate and the housing; when more than two partition plates are arranged, two types of micro-channels are formed, micro-channels formed between the partition plates and required by chemical reaction belong to the first type, and micro-channels formed between the partition plates and the housing of the reactor and required by chemical reaction belong to the second type; multiple support forms can be adopted for a catalyst of the reactor: a catalyst required by reaction is directly supported on the partition plates, and the catalyst required by reaction is filled in the micro-channels in a particle form or in a manner of being supported on a foam metal. When the catalyst is deactivated or is required to be unsupported after reaction, only the catalyst and the partition plate are required to be extracted from the housing of the reactor, so that a problem about separation of the catalyst from the micro-channel reactor is solved; in addition, the reactor adopting such a structural form is low in manufacturing cost, and has the advantage of engineering scale-up.