In the context of the new dual-cycle development model, the Long Triangle, as the main development pillar of China's economic development, aims to enhance the quality development level of the digitization and industrialization, and achieve the deep development of the two. Based on the differential equation, this paper presents the problems of the linkage and coordination between digitization and sustainable development of manufacturing in Long Triangle. The countermeasures based on panel data of three provinces and a city in Long Triangle from 2011 to 2019, an index system of quality of digitization and productivity has been established, and spatio-temporal evolution characteristics of joint level and problems in the process of joint coupling are analyzed. The results show that from 2011 to 2019, the level of linkage and coordination between economic digitization and sustainable development of production in Long Triangle region is increasing, but the overall level is not high and the spatial difference is large. There are also significant differences between rank and benign cooperation; The key obstacle factors in each province are both relatively concentrated and different.