From the perspective of global value chain, this paper measures the length of production of China’s manufacturing sector based on the data of WIOD, and constructs a theoretical model of carbon emission effect in the production length of manufacturing, tests the effect of extended production length of manufacturing sector on carbon emissions empirically. The main conclusions are: (1) The overall extension of production length of manufacturing, and the structural effects brought about by it can reduce carbon emissions effectively; (2) The effect of global and domestic production length on carbon emissions is reversed. The global production part of the production length will increase the carbon emissions of manufacturing, and the increase in the domestic production length will significantly promote the manufacturing carbon emission reduction.