A negative electrode includes a negative current collector and a negative active material layer. The negative active material layer includes a silicon-based material. A weight ratio R of the silicon-based material to a total weight of the negative active material layer and an absolute strength σ of the negative current collector satisfy the following formula: K=σ/(1.4×R+0.1), where K is a relation coefficient, and the relation coefficient is greater than or equal to 4,000 N/m. The electrochemical device can effectively mitigate XY expansion and deformation of the negative active material layer by using the foregoing negative electrode, thereby enhancing cycle performance and safety performance of the electrochemical device.