Achieving high-efficiency treatment with minimal energy consumption remains a major challenge for rural wastewater treatment (RWWT) using conventional activated sludge processes (ASP). This study presents a novel micro- and nano-bubble aeration ASP system (Mi/NaB-AS) specifically designed to overcome the intrinsic limitations of conventional bubble aeration (CBA). Comprehensive assessment of aeration performance, including volumetric mass-transfer coefficient (KLa), oxygen transfer rate (OTR), and oxygen transfer efficiency (OTE), demonstrated that Mi/NaB-A enhanced KLa, OTR, and OTE by 8-, 9-, and 6-fold, respectively, relative to CBA, indicating that superior oxygenation derives from the unique physicochemical properties of Mi/NaBs rather than elevated oxygen dosing. The Mi/NaB-AS achieved excellent operational stability, consistently removing 98% of COD and 98% of NH4+-N over 120 days. A key innovation of the Mi/NaB-AS is its ability to leverage the extended residence time and interfacial activity of Mi/NaBs to rapidly initiate and sustain partial nitrification (PN). Reactive oxygen species generated during bubble collapse selectively inhibited nitrite-oxidizing bacteria (NOB) while enriching ammonia-oxidizing bacteria (AOB), establishing a rapid, stable, and energy-efficient PN pathway. Energy analyses further confirmed a 6.9-fold improvement in energy efficiency (22,080 mg NH4+-N kW- 1 center dot h- 1) compared with CBA (3200 mg NH4+-N kW- 1 center dot h- 1). Metagenomic and 16S rRNA profiling revealed substantial microbial community restructuring, with PN activity increased 2.0-fold and nitrification genes hao and amoA elevated by 2.9- and 6.3-fold, respectively. Overall, Mi/NaB-AS provides a highly efficient, lowenergy, and sustainable solution for RWWT, demonstrating its potential to replace conventional CBA systems and enable stable, high-rate PN, representing a significant advancement in rural wastewater treatment technology.