As a new type of product with small size, large transmission capacity, low loss and environmental friendliness, superconducting cable can effectively reduce the loss of power transmission and reduce CO2 emissions caused by power loss. Currently, due to the lack of wide-scale application of superconducting cables, their energy saving and CO2 emission reduction effects are still unclear. Therefore, based on the data of existing superconducting cable demonstration projects and combined with the applicable scenarios of superconducting cable in the future, this paper analyzes and investigates the CO2 emissions of superconducting cables, compares them with those of traditional cables, and estimates the emission reduction of superconducting cables compared to traditional cables. With this estimation result, the CO2 emission reduction in the future applicable scenarios of superconducting cables is predicted. The prediction results show that using superconducting cables with decompression refrigeration to replace steel plant substations and traditional transmission cables has the most significant saving effect, which will save about 1.1806 million tons of CO2 emissions per year, which is 91.48% lower than that of conventional cables. In power grid application, if the length of superconducting cable exceeds 0.66 km, the emission reduction effect is better than that of 2-circuit-1200 XLPE cables. If the length of superconducting cable exceeds about 1.2 km, the CO2 emission reduction effect is better than that of 4-circuit-630 XLPE cables.