A circulation smoke discharging system includes: a circulation smoke discharging apparatus configured to receive setting output information of a treatment instrument apparatus including a treatment instrument, feed predetermined gas, and perform circulation smoke discharging by sucking smoke generated in a body cavity and gas in the body cavity; a pump for the circulation smoke discharging; an input voltage determination unit configured to determine a pump input voltage corresponding to a circulation flow rate of the circulation smoke discharging in accordance with the setting output information of the treatment instrument apparatus; and a circulation flow rate control unit configured to control the circulation flow rate by outputting the pump input voltage to the pump.