The invention relates to a construction waste comprehensive utilization method and device, the process is as follows: a, collecting and crushing construction waste; b, using an electromagnetic separation method to remove iron impurities, and using a gravity separation process to remove impurities such as living garbage; c, crushing and grinding; d, passing waste fine powder by a cyclone preheater to heat in a partition rotary kiln furnace hearth to obtain an oxide mixture; e, cooling the decomposed oxide mixture in a water cooling pool; f, filtering and separating a decomposed liquid mixture; and g, performing carbonizing reaction of filtrate and carbon dioxide to obtain light calcium, wherein filter residue is used as a raw material of a refractory material. The device comprises a crusher, an electromagnetic separator, a gravity separator, a crushing grinding machine, the cyclone preheater, a partition rotary kiln, a moisture separator, the water cooling pool, a filter, the refractory material, a warehouse carbonation reactor, a carbon powder warehouse, a waste heat power generation unit and an air separation unit. A variety of available components of the construction waste are effectively separated, available resources are fully used, the nature pollution of the construction waste is reduced, and farmland occupation can be reduced and avoided.