The application provides a porous film and a lithium-ion battery. The porous film according to the present application has excellent adhesion, and the pore structure of the porous film can still be well maintained after being immersed in the electrolyte, thereby reducing the probability of pore blockage of the porous film and allowing the lithium-ion battery to have high ionic conductivity. Therefore, the rate performance of the lithium-ion battery is greatly improved, and the lithium-ion battery provided has excellent rate performance and cycle performance.