The present disclosure relates to a lithium-ion battery bonding agent and a lithium-ion battery comprising the same. The bonding agent may be a polymer comprising structural units represented by Formula I, Formula II, Formula III, and Formula IV, and has an average molecular weight of 500,000 to 1.2 million. The bonding agent may be incorporated into at least one of a positive film, a negative film, a separator, and an electrolyte in the battery. The bonding agent can significantly improve the flexibility of the positive film, avoid processability and battery performance issues caused by the electrode film being too brittle, and help improve the compact density and battery energy density.