On the basis of triple-bottom-line performance evaluation, the system of indicator and the model of evaluating are established in this paper on the performance of Iron and Steel Enterprises. With the sample of 10 listed data between 2009 and 2011 of China's Iron and Steel Enterprises, this paper also conducts an empirical study on tripe performance evaluation and sets out each one's overall performance to carry out a synthetic evaluation on China’s Iron and Steel Enterprises under low carbon economy.