Energy intensity has been a major assessment indicator in the design of energy saving policies, and it is one of the eight binding indicators of the target responsibility system for officials' performance evaluation in the 11th Five-Year Plan in China. However, the accuracy of measurement of energy intensity depends to a large extent on the reliability of GDP data. This paper revises the GDP growth rate with nighttime lighting data and recalculates the rate of energy intensity reduction for each province during the 11th Five-Year Plan in China. Our results show that the GDP growth rate of some provinces has been exaggerated. Further, although the energy intensity of all provinces showed a significant downward trend during the 11th Five-Year Plan, some provinces failed to meet the target of energy intensity reduction. These results suggest that when designing energy conservation policies, cross-evaluation indicators should be included to improve the effective implementation of policies.