Based on several classic models of static depreciation of fixed assets, linear dynamic depreciation models, accelerated dynamic depreciation models with the changing of depreciation base and accelerated dynamic depreciation models with the changing of depredation rate are constructed according to intrirtsie law of each depreciation amount of each depreciation model. The change from static depreciation model to dynamic depreciation model is better realized. On the basis of this, this paper tries to seek the Common law of each periodic depreciation amount of all dynamic depreciation models and constructs the common model of dynamic depreciation of all assets in order to provide the common models for enterprises to input the relative initial condition to directly use fixed assets dynamic depreciation aeeording to their real situation to calculate the dynamic depreciation amount of each period of fixed assets.