Wastewater treatment is a complex process with high energy consumption and low efficiency. Different from the traditional concept of wastewater treatment, the pollutants contained of wastewater can be regarded as energy materials or as the raw materials of other products to be havested to reduce the energy consumption. The forms of the pollutants' embodied energy in wastewater were examined by employing two calculation methods and taking sewage and coking wastewater as examples. Moreover, two possible path ways for the utilization and maximization of the recovery of embodied energy during the wastewater treatment were discussed. The different forms of energy consumption and their causes in wastewater treatment process were analyzed based on thermodynamic laws and quality characteristics of the wastewater, with reasonable assumptions. The laws of energy transfer and distribution of two specific cases are expressed by the energy flow diagram. Some possible energy-saving approaches and wastewater treatment methods in the future are predicted by comparing different energy saving technologies. Based on in-depth understanding of the embodied energy in wastewaters, valuable elements such as nutrients (nitrogen, phosphorus) and heavy metals can be separated and recovered, and water resources can be reused by combining with related industries and technologies. Therefore, the goal of energy saving can be achieved by the indirect compensation of energy consumption in the wastewater treatment process.