With the global low-carbon revolution growing rapidly，the development patterns and technical plans of low-carbon electricity emerge in an endless stream.It is imperative to make precise evaluation of the production efficiency of low-carbon electricity.A new line of thought for low-carbon electricity benefits evaluation with the low-carbon index as the core is proposed.Based on the data envelopment analysis（DEA），the super efficiency DEA model is improved by principal component analysis，with the unexpected error caused by non-radial relaxation variables and the information overlap existing in low-carbon evaluation indices considered.The low-carbon input preference factor and low-carbon input principal component are also introduced while the objective function of optimization model is modified to improve model accuracy.Finally an example is given to prove the validity and correctness of the model with low-carbon electricity production efficiency calculation，comprehensive evaluation，model comparison and parameter sensitivity analysis of the low-carbon power systems in different provinces（cities）.