A multifunctional vehicle-mounted refrigerator with a plug-in battery , comprising a refrigerator box , an openable cover arranged on a top of the refrigerator box , a refrigerating chamber and a freezing chamber that are arranged side by side in the refrigerator box , and a compressor that is installed at a bottom of one side of the refrigerator box ; wherein the vehicle-mounted refrigerator further comprises two rollers arranged at one end of the bottom of the refrigerator box and a telescopic pull rod arranged at another end of the refrigerator box ; wherein a battery chamber is defined in a side wall of the refrigerator box , and a battery is inserted into the battery chamber , characterized in that the battery comprises a battery box and a battery cover arranged at an upper end of the battery box , wherein laterally movable buckle plates are symmetrically arranged between two ends of the battery cover , wherein two ends of the buckle plates extend out of respective ends of the battery cover , a central portion of the buckle plates is disposed outside the battery cover , and the buckle plates at both ends are connected by an elastic piece , which is disposed in a limiting groove defined in an inner side of the battery cover , wherein a conductive socket is arranged in the battery chamber , and a conductive plug disposed on a side of the battery box is plugged into the conductive socket , wherein at least one groove is defined in an inner side wall of the box cover , and a detachable fruit cutting board is embedded in the at least one groove , wherein a rotating blocking plate is installed at one end of the at least one groove , and a convex plate is installed on a side wall at another end, wherein both ends of the fruit cutting board are restricted in the groove by the rotating blocking plate and the convex plate , and an inner bottom surface of the groove is evenly distributed with raised blocks . wherein the vehicle-mounted refrigerator further comprises two rollers arranged at one end of the bottom of the refrigerator box and a telescopic pull rod arranged at another end of the refrigerator box ; wherein a battery chamber is defined in a side wall of the refrigerator box , and a battery is inserted into the battery chamber , characterized in that the battery comprises a battery box and a battery cover arranged at an upper end of the battery box , wherein laterally movable buckle plates are symmetrically arranged between two ends of the battery cover , wherein two ends of the buckle plates extend out of respective ends of the battery cover , a central portion of the buckle plates is disposed outside the battery cover , and the buckle plates at both ends are connected by an elastic piece , which is disposed in a limiting groove defined in an inner side of the battery cover , wherein a conductive socket is arranged in the battery chamber , and a conductive plug disposed on a side of the battery box is plugged into the conductive socket , wherein at least one groove is defined in an inner side wall of the box cover , and a detachable fruit cutting board is embedded in the at least one groove , wherein a rotating blocking plate is installed at one end of the at least one groove , and a convex plate is installed on a side wall at another end, wherein both ends of the fruit cutting board are restricted in the groove by the rotating blocking plate and the convex plate , and an inner bottom surface of the groove is evenly distributed with raised blocks . <EOS>