On the basis of ISO value chain methodology; this paper estimates the influence of standardization on relevant value chain activities of thermal power enterprises. Taking M Thermal Power Plant as an example, this paper determines the value chain of enterprises first and then evaluate the influence of standardization on coal purchasing, power generation, safety supervision and materials management activities based on expert assessment method and BP neural network analysis method. It can be known through estimation that, from 2011 to 2014, the annual economic benefit of standardization in M Thermal Power Plant is about RMB 5. 8 million (have an influence about 2% on annual profit). At the same time, this paper evaluates the environmental benefits of standardization. After the implementation of the new environmental standards, M Thermal Power Plant reduces the discharge of SO2 for about 770 t, NOX about 4,870 t and soot and dust about 95t every year from 2011 to 2014. The standardization has a significant environmental benefits and effects.