Abstract: The mechanism of municipal bonds on economic sustainable growth is more complex. It is important to judge whether the two parties have the threshold effect to determine the structural differences in the mechanism of the effect of the debt ratio on the economic growth in different regions of the threshold, and to judge the efficiency of municipal bonds scientifically, the risk state and the corresponding management. Based on China′s inter provincial panel data, this paper introduces the threshold effect from the perspective of fiscal revenue, and discusses the influence mechanism of provincial municipal bonds on China′s sustainable economic growth. The results show that municipal bonds have significant threshold effect on economic growth, there is a left-flattened S-shaped relationship between municipal bonds and economic sustainable development, the first turning point is about 120%, in the vicinity of which the left side of the slope is relatively slow, the right side of the slope is steep; the second turning point is about 140%, different threshold ranges show different influencing mechanisms of municipal bonds on China′s economy. The precise quantitative conclusion of this paper provides an important scientific basis for the design and improvement of China′s municipal bonds policy. The conclusion of the conclusion of this paper is that the debt issuance of the less developed areas in China is late. Although the current debt is generally higher than the economically developed area, the effect on economic growth is very obvious. Therefore, on the basis of strengthening the management of debt risk, the debt scale can be properly increased, and the central finance can also be given some policy support.

Key words: municipal bonds, sustainable economic growth, debt rate, income threshold effect, nonlinear mechanism