Ensuring that underdeveloped counties share the development achievement and realize coordinated development is indispensable goals of China's targeted poverty alleviation policy.Based on the county data from 2006 to 2019 in China,this paper conducts an empirical analysis using the convergence equation of economic growth.The results show that:1)China's county economy has convergence,targeted poverty alleviation policy can enhance the economic growth rate of underdeveloped counties(β convergence).According to the mechanism analysis,industrial structure upgrade and financial efficiency improvement are the keys to promoting the economic convergence,which is inconsistent with the hypothesis of either Neoclassical Growth Theory,New Economic Geography or Endogenous Growth Theory.2)Further analysis shows that the economic convergence of China's counties stems from reducing the gap between counties within the poor and non-poor groups(within club convergence)during the period of Targeted Poverty Alleviation.Pairing assistance by the eastern region-western region cooperation policy cannot narrow the economic gap between poor counties and others(intergroup club convergence).Taking into account both efficiency and equity,China should follow the comparative advantages of underdeveloped counties,adjust the pairing assistance relationships and improve assistance methods between the eastern region and the western region,and strengthen the management capacity of the government.To realize common prosperity,the government should revitalize underdeveloped counties through industrial,financial,and taxation policies.