The invention provides a manufacturing workshop carbon discharge comprehensive evaluation method which includes the following steps: through establishment of manufacturing workshop machining process schema description, the manufacturing workshop is decomposed into three layers: a device layer, a part layer and a workshop layer from bottom to top; based on a full-life-circle evaluation method, energy consumption footprint and carbon footprint calculation methods for the device layer, the part layer and the workshop layer are constructed; then according to a device-working procedure-part-workshop hierarchical structure, particle decomposition and evolution are carried out on carbon discharge activities in the manufacturing workshop and based on an environment efficiency concept, a plurality of carbon efficiency evaluation indexes including carbon discharge utilization rate, production-carbon efficiency and economical-carbon efficiency and the like under different evaluation granularities are established; and at last, a multi-distribute concession method of carbon discharge comprehensive evaluation under different evaluation granularities of the manufacturing workshop is established. The method is capable of helping enterprises to find out weak links of energy conservation and emission reduction and also capable of providing data support to production decisions of the enterprises.