The invention provides a remained energy utilization system for coke oven flue gas. The remained energy utilization system for coke oven flue gas comprises a smoke gas collecting passage, a smoke gas collecting valve, a remained energy heat exchange module, a draught fan, a smoke gas return passage and a smoke gas exhaust passage, wherein the smoke gas collecting passage is connected with a coke oven; the smoke gas collecting valve, the remained energy heat exchange module and the draught fan are sequentially arranged on the smoke gas collecting passage; the smoke gas collecting valve is positioned between the coke oven and the remained energy heat exchange module; the smoke gas return passage is connected with the smoke gas collecting passage through a smoke gas return valve, and is connected with an original chimney of the coke oven; the smoke gas exhaust passage is connected with the smoke gas collecting passage through a smoke gas exhaust valve. The remained energy utilization system has the advantages that low-pressure superheated steam can be generated for being used by plant users; the smoke gas exhaust passage and the smoke gas return passage are also installed, so that the used smoke gas achieves a heat standby effect on the original chimney in the process of being exhausted into atmosphere; the fast switching of the smoke gas passage is realized; a sectionalizing remained energy utilization system is fast and convenient.