Municipal wastewater treatment process could be attributed to energy-intensity integrated technology. Research advance is summarized across from energy comsuption analysis, energy audit and management to development on energy saving processes or performance modes. The author think that due to theory frame of energy consumption and energy efficiency not being established, analytical approaches and evaluation means lag behind practical application. So consequent trend of intercrossing and syncretizing between biothermodynamics, chemical thermodynamics, energy engineering and basic knowledge in wastewater treatment domain would emerge. The trend will promote systematism and diversification occur in study on processes energy consumption and energy efficiency, and promote all kinds of research productions to be integrated and popularized.