A secondary battery, comprising: a positive electrode plate, a negative electrode plate, a separator disposed between the positive electrode plate and the negative electrode plate, and an electrolyte solution, the negative electrode plate including a negative electrode current collector and a negative electrode active material layer provided on at least one side of the negative electrode current collector, and the electrolyte solution including an organic solvent and a lithium salt, wherein the negative electrode active material comprises a core structure and a polymer network coating layer coated on at least a part of the surface of the core structure, the core structure comprises SiO x (0 < x < 2), the polymer network coating layer accounts for at least 0.5 mass% and at most 10 mass% of the total mass of the negative electrode active material, and the network coating layer has a network structure formed by cross-linked polymers and is derived from a polymer having one or more functional groups selected from a group consisting of cyano group, amide group, imide group, sulfonyl group, carboxyl group and sulfonyl group; and the lithium salt comprises a primary lithium salt represented by Formula I: in which Formula I, R 1 and R 2 each independently represent a fluorine atom, a fluoroalkyl group having 1-20 carbon atoms, or a fluoroalkoxy group having 1-20 carbon atoms, and n is an integer of 1, 2 or 3, the mass percentage concentration of the primary lithium salt in the electrolyte solution is in the range of 10% to 20%, the lithium salt further comprises a secondary lithium salt, which is selected from one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium trifluoromethyl sulfonate, and lithium hexafluoroarsenate, and the mass percentage concentration of the secondary lithium salt in the electrolyte solution is in the range of 3% to 5%. the negative electrode active material comprises a core structure and a polymer network coating layer coated on at least a part of the surface of the core structure, the core structure comprises SiO x (0 < x < 2), the polymer network coating layer accounts for at least 0.5 mass% and at most 10 mass% of the total mass of the negative electrode active material, and the network coating layer has a network structure formed by cross-linked polymers and is derived from a polymer having one or more functional groups selected from a group consisting of cyano group, amide group, imide group, sulfonyl group, carboxyl group and sulfonyl group; and the lithium salt comprises a primary lithium salt represented by Formula I: in which Formula I, R 1 and R 2 each independently represent a fluorine atom, a fluoroalkyl group having 1-20 carbon atoms, or a fluoroalkoxy group having 1-20 carbon atoms, and n is an integer of 1, 2 or 3, the mass percentage concentration of the primary lithium salt in the electrolyte solution is in the range of 10% to 20%, the lithium salt further comprises a secondary lithium salt, which is selected from one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium trifluoromethyl sulfonate, and lithium hexafluoroarsenate, and the mass percentage concentration of the secondary lithium salt in the electrolyte solution is in the range of 3% to 5%.