A separated coolant circulation structure for a water-cooled power generator, comprising: a cooling circulation channel for a stator bar to cool heat of a stator bar winding, wherein the stator bar winding extends between a collector end and a turbine end; and a cooling circulation channel for a connector ring to cool heat of a connector ring, wherein the cooling circulation channel for the stator bar and the cooling circulation channel for the connector ring form separate coolant supply paths to improve cooling efficiency and reduce a pump load, wherein the cooling circulation channel for the stator bar includes: an annular coolant supply ring for a collector end which is connected to a coolant inlet pipe, through which a coolant flows; a stator inner channel for supplying the coolant to the stator winding, of which an inlet terminal positioned at a collector end side is connected to the coolant supply ring for the collector end; and an annular coolant discharge ring for a turbine end that is connected to an outlet terminal of a turbine end side of the stator inner channel, and wherein the cooling circulation channel for the connector ring includes: the coolant supply ring for the collector end, a connector ring outer channel for annularly enclosing a circumference of the connector ring, of which an inlet terminal is connected to the coolant supply ring for the collector end to receive the coolant, and an annular coolant discharge ring for the collector end that is connected to an outlet terminal of the connector ring outer channel. a cooling circulation channel for a stator bar to cool heat of a stator bar winding, wherein the stator bar winding extends between a collector end and a turbine end; and a cooling circulation channel for a connector ring to cool heat of a connector ring, wherein the cooling circulation channel for the stator bar and the cooling circulation channel for the connector ring form separate coolant supply paths to improve cooling efficiency and reduce a pump load, wherein the cooling circulation channel for the stator bar includes: an annular coolant supply ring for a collector end which is connected to a coolant inlet pipe, through which a coolant flows; a stator inner channel for supplying the coolant to the stator winding, of which an inlet terminal positioned at a collector end side is connected to the coolant supply ring for the collector end; and an annular coolant discharge ring for a turbine end that is connected to an outlet terminal of a turbine end side of the stator inner channel, and wherein the cooling circulation channel for the connector ring includes: the coolant supply ring for the collector end, a connector ring outer channel for annularly enclosing a circumference of the connector ring, of which an inlet terminal is connected to the coolant supply ring for the collector end to receive the coolant, and an annular coolant discharge ring for the collector end that is connected to an outlet terminal of the connector ring outer channel. an annular coolant supply ring for a collector end which is connected to a coolant inlet pipe, through which a coolant flows; a stator inner channel for supplying the coolant to the stator winding, of which an inlet terminal positioned at a collector end side is connected to the coolant supply ring for the collector end; and an annular coolant discharge ring for a turbine end that is connected to an outlet terminal of a turbine end side of the stator inner channel, and wherein the cooling circulation channel for the connector ring includes: the coolant supply ring for the collector end, a connector ring outer channel for annularly enclosing a circumference of the connector ring, of which an inlet terminal is connected to the coolant supply ring for the collector end to receive the coolant, and an annular coolant discharge ring for the collector end that is connected to an outlet terminal of the connector ring outer channel. the coolant supply ring for the collector end, a connector ring outer channel for annularly enclosing a circumference of the connector ring, of which an inlet terminal is connected to the coolant supply ring for the collector end to receive the coolant, and an annular coolant discharge ring for the collector end that is connected to an outlet terminal of the connector ring outer channel.