<p>The applicable conditions and scope of the underground sewage treatment plant include a small amount of sewage, less available land on the ground, special requirements for the above-ground landscape, low groundwater level, easy-to-excavate geology, and the buried depth of the sewage return pipe is not very large. It is not under the main road, has a certain distance from residential buildings, is not a depression, does not accumulate rainwater, and the sewage discharge requirements are not very strict. The underground sewage treatment plants are suitable for construction in areas where thermal insulation needs to be considered, less requisitionable land area, and higher environmental requirements. The results of the underground landscape design study showed that the design of principles, features, styles, water ecologies, a combination between community friendly and ecologically friendly, operations and maintenance cost of the underground landscape should be emphasized. The construction of the ecological complex will lead the sewage treatment plant exchange from minus assets to ecological positive assets, which will meet the needs of future urban social economic development and environmental protection. The results of the development direction exploration study showed that innovation in the design concept, breakthroughs of key sewage treatment technology, and variation of investment and operation mode can reduce the land occupation investment and operation cost, and the underground sewage plant with large-scale and semi-underground mode owes broader prospects for development.</p>