Cover plate assembly of novel secondary battery and secondary battery

The utility model discloses a novel cover plate assembly of a secondary battery, which comprises a cover plate, a lower insulating part and two groups of pole assemblies, the cover plate is provided with an electrode leading-out hole, the lower insulating part is provided with a lower insulating part through hole, and the pole assemblies extend upwards after sequentially penetrating through the lower insulating part through hole and the electrode leading-out hole; the pole assembly comprises a pole main body, a sealing ring and an upper insulating part; the middle part of the pole main body protrudes upwards and then is integrally formed into a pole convex part, the sealing ring sleeves the periphery of the pole convex part, after the cover plate is connected with the lower insulating part, the bottom surface of the cover plate is propped against the top surface of the sealing ring, and the upper insulating part is fixedly connected in a gap between the inner wall of the electrode lead-out hole and the outer