The invention relates to a device for recovering carbon sources in domestic sewage by coupling flocculation with separation as well as a use method of the device. The device comprises a grille, an efficient coagulation tank, a water inlet pump, an electromagnetic flowmeter, a water inlet electromagnet, a water inlet pressure gauge, a sand filter, a water outlet pressure gauge, a water outlet electromagnet, a backwashing water inlet electromagnet, a backwashing pump, a backwashing water outlet electromagnet, a flocculant adding device and a coagulant aid adding device. The device is reasonablein structural design, and can efficiently treat domestic sewage containing low-concentration organic matters and recover organic matters in the sewage by chemical flocculation and physical separationmeans so as to realize sustainable development of a sewage processing technology.