The tax treatment of loan interest after the enterprise is converted into a fixed asset is as follows:

1. The loan interest is included in the cost: the enterprise uses the loan to pay for the purchase value of the fixed assets during the conversion process. When calculating corporate income tax, loan interest can be included in the cost, which can be used as an expense for the enterprise to reduce the tax base and reduce the burden of corporate income tax.

2. Loan interest deduction: If the current liabilities and long-term liabilities in the enterprise's balance sheet are higher than the sum of fixed assets and intangible assets, and the net liability is positive, the enterprise can calculate the loan interest paid. Financial expenses can be deducted before tax to reduce taxable income.