Methane produced during sewage treatment is a source of greenhouse gases which cannot be ignored. The estimate of methane emissions during wastewater treatment has an important significance for proposing methane reduction measures on the technical and economic feasibility. In this paper, the status of CH4 emissions during sewage treatment of Henan Province is described. By obtaining the sewage treatment-related data and emission factor in Henan Province in 2010,CH4 emissions in the year is estimated. The results show that CH4 net emissions during domestic wastewater treatment is 21,764.10 tons in 2010 and that can evaluate the greenhouse effect and provide a basis for environmental management.