Provided is a method for economically and stably producing a high-quality polycarbonate-polyorganosiloxane copolymer excellent in, for example, transparency and impact resistance in a continuous manner. Specifically, provided is a method of continuously producing a polycarbonate-polyorganosiloxane copolymer, the method including a step (A) of continuously or intermittently taking a polymerization reaction liquid, which is obtained by polymerizing a dihydric phenol-based compound, a carbonate precursor, and a polyorganosiloxane in the presence of an alkaline compound aqueous solution and a water-insoluble organic solvent, out of a reactor, the step (A) including the following step (a-1) and the following step (a-2), the method using a dissolution tank for dissolving the dihydric phenol-based compound in the alkaline compound aqueous solution to prepare an alkaline compound aqueous solution of the dihydric phenol-based compound to be used in each of both the step (a-1) and the step (a-2), the step (a-2) including, before mixing a polycarbonate oligomer and the dihydric phenol-based compound, mixing the alkaline compound aqueous solution and the alkaline compound aqueous solution of the dihydric phenol-based compound prepared in the dissolution tank: step (a-1): a step of mixing the alkaline compound aqueous solution of the dihydric phenol-based compound prepared in the dissolution tank and the polycarbonate precursor, followed by a reaction of the mixture in the presence of the water-insoluble organic solvent to produce the polycarbonate oligomer; and step (a-2): a step of continuously or intermittently taking the polymerization reaction liquid, which is obtained by mixing the alkaline compound aqueous solution of the dihydric phenol-based compound prepared in the dissolution tank, the polycarbonate oligomer obtained in the step (a-1), and the polyorganosiloxane, and polymerizing the mixture in the presence of the water-insoluble organic solvent, out of the reactor.