This article mainly clarifies the relationship between the debt risk，the fiscal risk and the public risk theoretically and logically，analyzes the existing problems in debt management，looks at debt value from the two dimensions of time and space，and puts forward requirements the balance between the debt risk and public risk is taken as the basic criterion for the sustainability of local government debt. Finally，four basic principles for the sustainability of local government debt are put forward，namely，the matching of financial rights and powers，the correspondence between the debt scale and solvency，the symmetry of risks and returns，and the coordination of short-term debt and long-term debt. At the same time，relevant policy recommendations are put forward，including：firstly，reform the local government performance appraisal method. The second is to improve the fiscal relationship between the central and the local governments to prevent the risk of local government debt from rising. The third is to establish a debt performance management system to reduce the debt risks and public risks. The fourth is to establish a fiscal and financial coordination mechanism to reduce the risk of debt default.