10 listed companies in China with more than 170 wastewater treatment plants in 2016 are taken as cases to estimate the shadow price of carbon emissions in the process of wastewater treatment by using the parametric directional distance function approach. The market method is introduced to formulate the related policies for carbon emissions, and a method for the establishment of the carbon trading market and distribution of carbon emissions is provided so as to improve the efficiency of reducing carbon emissions in the wastewater treatment industry and to fully control the carbon emissions.