Abstract：By introducing the imperfect credit market into the Schumpeterian growth model with technology transfer，this article makes some theoretical explanations on the "club convergence" of economic growth．And then，we obtain the nonlinear correlation between financial develop ment and economic growth from the dynamic evolution of technological gap．To further test the theoretical conjecture，we use a dynamic panel threshold model to make an empirical test，and find that the impact of financial development on economic growth has a double threshold charac teristic．Specifically，when the level of financial development is lower than the first threshold， one country's economic growth will not converge to the growth rate of global frontier，exhibiting a financial constraint effect；when the level is between the two thresholds，the probability of convergence will improve a lot；finally，when the counterpart exceeds the second threshold， the pulling effect will gradually decline，showing a prominent property of diminishing margin， which coincides with the theoretical conjecture and provide an important reference for the finan cial development in China．

Keywords：Financial Development；Economic Growth Convergence；Technology Gap