The invention provides an electrochemical model based method for early warning for a lithium battery, including establishing a three-dimensional electrochemical model for the lithium battery, and dividing the lithium battery into three portions respectively including a positive electrode, a negative electrode and a separator; performing spatial discretization on the three-dimensional electrochemical model according to a preset accuracy to establish the four-dimensional spatial coordinates of the lithium battery; obtaining a current lithium ion concentration in each position of the lithium battery by simulation based on the four-dimensional space coordinates, a historical lithium ion concentration and a historical diffusion coefficient of the lithium battery; and performing early warning for the lithium battery according to the current lithium ion concentration in each position. The method adopts the volumetric SOC or surface SOC of the lithium battery for operation management, which is direct and objective, and can be is applied to most external environments.