A continuous reactor for preparing a positive electrode active material for a lithium secondary battery, the continuous reactor comprising: a non-rotating cylinder 10 having a reaction chamber 11 therein; a stirring motor 20 disposed at one side of the cylinder 10; a stirring rod 30 coupled to a motor shaft 21 of the stirring motor 20 and included in the reaction chamber 11 so as to be spaced from the wall surface of the reaction chamber 11; at least one flange unit 12 provided on the cylinder 10, with at least one reactant inlet port 13 provided on the at least one flange unit so as to communicate with the reaction chamber 11 and configured to introduce a reactant into the reaction chamber; a reaction product outlet port 14 provided at the other side of the cylinder 10 so as to communicate with the reaction chamber 11 and configured to discharge a reaction product from the reaction chamber; a temperature control unit 40 disposed in the wall portion of the cylinder 10, the temperature control unit 40 comprising a ring-shaped refrigerant chamber 41 and a refrigerant filled in the refrigerant chamber; a pulverizing unit 50 provided in the reactant inlet port 13 and configured to pulverize particles of the reactant that is introduced through the reactant inlet port; a flow rate sensor 60 provided in the reactant inlet port 13 and configured to sense the flow rate of the reactant; a flow rate control unit 70 configured to control the flow rate of the reactant, which is introduced through the reactant inlet port 13, on the basis of flow rate data sensed by the flow rate sensor 60; a particle size control unit; and the temperature control unit 40, the flow rate control unit 70 and the particle size control unit being integrally provided in the continuous reactor. a non-rotating cylinder 10 having a reaction chamber 11 therein; a stirring motor 20 disposed at one side of the cylinder 10; a stirring rod 30 coupled to a motor shaft 21 of the stirring motor 20 and included in the reaction chamber 11 so as to be spaced from the wall surface of the reaction chamber 11; at least one flange unit 12 provided on the cylinder 10, with at least one reactant inlet port 13 provided on the at least one flange unit so as to communicate with the reaction chamber 11 and configured to introduce a reactant into the reaction chamber; a reaction product outlet port 14 provided at the other side of the cylinder 10 so as to communicate with the reaction chamber 11 and configured to discharge a reaction product from the reaction chamber; a temperature control unit 40 disposed in the wall portion of the cylinder 10, the temperature control unit 40 comprising a ring-shaped refrigerant chamber 41 and a refrigerant filled in the refrigerant chamber; a pulverizing unit 50 provided in the reactant inlet port 13 and configured to pulverize particles of the reactant that is introduced through the reactant inlet port; a flow rate sensor 60 provided in the reactant inlet port 13 and configured to sense the flow rate of the reactant; a flow rate control unit 70 configured to control the flow rate of the reactant, which is introduced through the reactant inlet port 13, on the basis of flow rate data sensed by the flow rate sensor 60; a particle size control unit; and the temperature control unit 40, the flow rate control unit 70 and the particle size control unit being integrally provided in the continuous reactor.