China’s economy has changed from the high-speed growth stage to the high-quality development stage

and improving total factor productivity has become the driving force for promoting the quality of economic development. This article analyzes how "new infrastructure" investment impacts high-quality economic development with total factor productivity as the core with the provincial panel data of China from 2003 to 2019

and empirically examines the impact of the "new infrastructure" investment on the high-quality economic development and the relevant mechanism

using the stochastic frontier model of spatial panel. The results show that: "new infrastructure" investment can significantly promote high-quality economic development

but different types of investment have significantly different impacts on economic development; there are significant spatial differences in the impact of "new infrastructure" investment on high-quality economic development; to a certain extent

"new infrastructure" investment is characterized by spatial agglomeration

which has two opposite effects on high-quality economic development

namely

"incentive" and "extrusion"

which leads to the nonlinear path of its impacts; in addition to directly promoting high-quality economic development

"new infrastructure" investment can also indirectly affect high-quality economic development through industrial structure

technological progress and resource allocation but different types of infrastructure investment have different influence paths.