There is provided a synthesis reaction system which synthesizes a hydrocarbon compound by a chemical reaction of a synthesis gas including hydrogen and carbon monoxide as main components, and a slurry having solid catalyst particles suspended in liquid and which extracts the hydrocarbon compound from the slurry. The synthesis reaction system includes a reactor main body which accommodates the slurry, a separator which separates the hydrocarbon compound included in the slurry from the slurry, a first flow passage which allows the slurry including the hydrocarbon compound to flow to the separator from the reactor main body, a second flow passage which allows the slurry to flow to the reactor main body from the separator, and a fluid supply nozzle which supplies a fluid toward at least any one of the separator, the first flow passage, and the second flow passage.