The present disclosure provides a secondary battery, the secondary battery comprises a positive electrode plate, a negative electrode plate, a separator and an electrolyte, the positive electrode plate comprises a positive current collector and a positive film, the positive film is provided on at least one surface of the positive current collector and comprises a positive active material, the negative electrode plate comprises a negative current collector and a negative film, the negative film is provided on at least one surface of the negative current collector and comprises a negative active material, the negative active material comprises graphite, and an average particle diameter of the positive active material represented by D50 and a thickness of the negative film represented by Hn satisfy a relationship: 6≤0.06Hn×(4−1/D50)≤31. The battery of the present disclosure has the characteristics of excellent dynamics performance and long cycle life at the same time.