A food preservation system is provided. The system includes a storage cabinet for storing foods, an electrolytic gas generator, a gas sensor and a control unit. The electrolytic gas generator is in fluid communication with the storage cabinet to output a first gas and a second gas to preserve the foods. The gas sensor is arranged in the storage cabinet to detect the concentration of the gases in the storage cabinet for obtaining gas concentration information which includes a first gas concentration and a second gas concentration. The control unit is electrically connected to the electrolytic gas generator and the gas sensor. According to the received gas concentration information, the control unit adjusts the applied voltage of the electrolytic gas generator to control the gas species generated by the electrolytic gas generator and the first and second gas concentrations in the storage cabinet.