A cash management system includes a plurality of cash settlement devices, a cashier device, and a cash management device, wherein the cash management device acquires the inventory number in each cash settlement device, and when a request is made to supply change funds, calculates the total number of banknotes or coins lacking relative to the preset post-replenishment inventory number thereof, wherein the cash management device instructs the cashier device to, when the total number is equal to or less than the inventory number in the cashier device, dispense banknotes or coins, the number of the dispensed banknotes or coins being required to allow the inventory number in the cash settlement device to reach the post-replenishment inventory number, and when the total number exceeds the inventory number in the cashier device, dispense banknotes or coins, the number of the dispensed banknotes or coins being calculated according to a preset calculation formula.