Lithium-sulfur battery, which has high theoretical specific capacity and energy density, is considered to be one of the next-generation of rechargeable batteries. But the "shuttle effect" still hinders its application. Here, carbon/gelatin microcapsule (C/GM) as a microreactor for sulfur cathode to suppress "shuttle effect" is prepared. The submicron-sulfur particles, which are synthesized with the regulation of gelatin, are encapsulated in the C/GM so that a region-limited electrochemical reaction can be realized. Benefiting from the micro-reactor inhibiting the dissolution of polysulfide, the initial discharge specific capacity of lithium-sulfur battery with C/GM cathode is up to 1259.0 mAh/g and still retains 961.0 mAh/g after 100 cycles. Due to the sustainable source and facile method, the C/GM cathode is promising for the application of lithium-sulfur batteries. (C) 2019 The Electrochemical Society.