In order to investigate the effect of super absorbent polymers (SAP) dosage on the carbon footprint of farmland ecological system, a field experiment was conducted to study carbon absorption, carbon emission, carbon cost, carbon efficiency and net carbon sink. The results indicated that although the application of SAP and various agricultural inputs increased farmland carbon footprint, they promoted the growth of crop and improved quality of crop dry biomass. Thus SAP and various agricultural inputs significantly improved the carbon absorption, reduced carbon cost and improved the efficiency of carbon and net carbon sink. Carbon cost of the treatment with 60kg/hm2 of SAP was the minimum, which was reduced by 25.6% compared with the control, while its carbon efficiency and net carbon sink were the maximum, which were increased by 35.3% and 30.6% than that of the control, respectively. Meanwhile, SAP could improve water use efficiency of winter wheat, the treatment with 60kg/hm2 of SAP was the best. The correlation analysis among different factors showed that positive correlations were found between water use efficiency, carbon sequestration, carbon efficiency and carbon net sink, while negative correlation was found between water use efficiency and carbon cost.