A centrifugal compressor system, comprising: a driving shaft which is rotationally driven; a driving gear which is connected to the driving shaft; a driven gear to which rotation of the driving gear is transmitted; a driven shaft which extends toward both end sides in a center axis direction of the driven gear; a first compression portion which is provided on a first end portion side in the center axis direction of the driven shaft, and compresses a fluid by rotation of the driven shaft; a second compression portion which is provided on a second end portion side in the center axis direction of the driven shaft, and compresses a fluid by rotation of the driven shaft; a pressure adjustment portion which uniformly adjusts a pressure of a space of a discharge side of the fluid in the first compression portion and a pressure of a space of a discharge side of the fluid in the second compression portion; characterized by comprising a heat exchanger which undergoes heat exchange with fluids which are discharged from the first compression portion and from the second compression portion and combines the fluids; a first connection line which connects a discharge port of the first compression portion and a first inlet nozzle of the heat exchanger; and a second connection line which connects a discharge port of the second compression portion and a second inlet nozzle which is different from the first inlet nozzle which is connected to the first connection line of the heat exchanger, wherein the pressure adjustment portion connects the first connection line and the second connection line at a position in which a distance ( l) in the first connection line from the discharge port of the first compression portion and a distance ( l) in the second connection line from the discharge port of the second compression portion are the same as each other. a driving shaft which is rotationally driven; a driving gear which is connected to the driving shaft; a driven gear to which rotation of the driving gear is transmitted; a driven shaft which extends toward both end sides in a center axis direction of the driven gear; a first compression portion which is provided on a first end portion side in the center axis direction of the driven shaft, and compresses a fluid by rotation of the driven shaft; a second compression portion which is provided on a second end portion side in the center axis direction of the driven shaft, and compresses a fluid by rotation of the driven shaft; a pressure adjustment portion which uniformly adjusts a pressure of a space of a discharge side of the fluid in the first compression portion and a pressure of a space of a discharge side of the fluid in the second compression portion; characterized by comprising a heat exchanger which undergoes heat exchange with fluids which are discharged from the first compression portion and from the second compression portion and combines the fluids; a first connection line which connects a discharge port of the first compression portion and a first inlet nozzle of the heat exchanger; and a second connection line which connects a discharge port of the second compression portion and a second inlet nozzle which is different from the first inlet nozzle which is connected to the first connection line of the heat exchanger, wherein the pressure adjustment portion connects the first connection line and the second connection line at a position in which a distance ( l) in the first connection line from the discharge port of the first compression portion and a distance ( l) in the second connection line from the discharge port of the second compression portion are the same as each other.