The invention discloses a pot cover. The pot cover comprises a pot cover body, a sterilization module and a control device, wherein the sterilization module comprises an
ultraviolet light-transmitting piece, and an
ultraviolet lamp arranged in an accommodating space between the pot body and the
ultraviolet light-transmitting piece, the ultraviolet lamp is electrically connected with the control device, and the pot cover body is provided with a cleaning module used for cleaning the light-emitting side of the
ultraviolet light-transmitting piece; the ultraviolet transmissivity is high, and the sterilizing effect is good. The invention further discloses a pot, wherein the pot comprises a pot body and the pot cover which covers the pot body; the ultraviolet transmissivity is high, and the sterilizing effect is good. The invention also discloses another pot, wherein a
thermal insulation module electrically connected with the control device is additionally arranged; the control device is arranged on the pot body and / or the pot cover body, and is connected with the
thermal insulation module or a temperature sensor; the ultraviolet transmissivity is high, and the sterilizing effect is good. The invention further discloses a method for preserving freshness of food in the pots; according to the method, after boiling of the food, when the temperature inside the pot is reduced to the preset sterilization temperature, the ultraviolet lamp is started, and when the temperature inside the pot is reduced to the preset sterilization temperature, the cleaning module is started; the operation is simple and convenient, the disinfection and sterilization effects are good, and the freshness preservation effect is good.