Abstract: Based on the panel data from 11 provinces and cities in the Yangtze River Economic Belt from 2015 to 2022, a comprehensive evaluation system for the modernization of traditional ethnic sports industry was constructed. The benchmark regression model, mediation effect model and spatial econometric model were used to systematically reveal the dual impact mechanism and spatial effects of new quality productive forces on the modernization of traditional ethnic sports industry. The benchmark regression analysis shows that the new quality productive forces has a significantly positive direct impact on its modernization, and the mediating effect further reveals that new quality productive forces can indirectly promote its modernization by improving the innovation efficiency of digital cultural industry. The results of regional heterogeneity testing show that there are significant regional differences in the promoting effect of new quality productive forces, with the strongest in downstream areas, followed by midstream areas and the weakest in upstream areas; while the spatial effect analysis shows that the improvement of new quality productive forces has a significantly positive direct effect on the modernization of traditional ethnic sports industry in the local area, but it has a negative spatial spillover effect on neighboring areas with an "echo effect". Based on this, suggestions are proposed as follows: stratified policies are taken to precisely cultivate new quality productive forces, the innovation efficiency of digital cultural industry improved to smooth the intermediary path, and regional collaboration linked to crack negative overflows.