The fixed assets of an enterprise may participate in the production and operation of the enterprise during successive accounting periods while still maintaining its original physical form. In this process, on the one hand, fixed assets will bring benefits to the enterprise, on the other hand, their value will gradually wear out and depreciate due to use, and gradually lose their service potential. Finally, they will be retired from use, which leads to the necessity of accounting for depreciation of fixed assets. The method of depreciation of fixed assets refers to the specific calculation method used to allocate the total amount of depreciation payable to fixed assets during their useful lifeIn the process of enterprise production and operation, the main reason for the waste of fixed assets is the tangible loss and intangible loss of assets. Tangible loss refers to the loss of use value and value caused by material wear and natural forces during the use of fixed assets. Intangible loss refers to the depreciation of the value of fixed assets caused by the progress of science and technology, the improvement of labor productivity and the change of market demand. For the above reasons, this part of the value of the losses of the fixed assets shall be allocated reasonably and systematically within the service life of the fixed assets according to the determined method, so as to form the expenses and be compensated from the income of each period.Depreciation refers to the systematic apportionment of the amount of depreciation in accordance with the determined method within the service life of a fixed asset. Among them, the amount of depreciation is the amount after deducting the estimated net residual value from the original value of the fixed assets that should be depreciated. In essence, depreciation is a kind of expense, except that this expense is the three paid monetary funds that have occurred in the previous period. However, the income of such expense is on the basis of the asset-generated accounting system, and the deduction of depreciation is necessary. In other words, the calculation of expense and profit and loss has the wrong effect. In addition, it is understood that depreciation is a cost-sharing process rather than an asset accountThe change in the market value of fixed assets, the book value of fixed assets (that is, there is a big difference. In fact, if the depreciation allowance for a fixed asset is withdrawn, its national assets are often zero or close to zero, but may still have a high market value.