The invention discloses a system and a method for industrially separating and purifying CO2 in mixed gas by a hydrate method. The system consists of a feed gas pretreatment system, a hydrate separation tower, a micro-bubble jet-loop reaction system, a column bottom hydrate decomposition system, a CO2 product collection system, a hydrate formation and decomposition heat comprehensive utilization system and a tail gas energy recovery system. The method integrates hydrate bubbling reaction technology, spraying reaction technology and micro-bubble jet reaction technology, adopts CO2 reflux displacement fractionation technology to improve the concentration of the CO2 in a hydrate phase, has simple separation technology and device and high separation rate and efficiency, comprehensively utilizes the formation heat and decomposition heat of the hydrate during refrigeration cycle, simultaneously recovers compression work of tail gas and cold energy for feed gas pretreatment, and has low energy consumption and cost during separation. The system and the method can be applied to industrial and continuous separation and purification of the CO2 in the mixed gas such as flue gas (CO2 / N2), IGCC synthetic gas (CO2 / H2), biomass synthetic gas (CO2 / H2), natural gas (CO2 / CH4), coalbed gas and the like.