Plant essential oils have become an important research hotspot in the field of natural products due to their excellent antioxidant activity. Maojian essential oil (MJEO) has shown significant research and development value due to its potential antioxidant mechanism. In response to the problems of high energy consumption and low efficiency in traditional extraction processes, this study used microwave-assisted hydrodistillation (MAHD) to extract MJEO. Based on single-factor experiments, response surface methodology (RSM) was applied to optimize the extraction parameters. The chemical composition of the obtained essential oil was subsequently analyzed using gas chromatography-mass spectrometry (GC-MS). The results showed that the extraction yield of MJEO was 0.1225% under the conditions of a microwave power of 406 W and a solid-to-liquid ratio of 1 : 4.1 g mL−1, and the CO2 emission of essential oil extracted by MAHD was reduced by 77.75% compared with traditional hydrodistillation (HD). GC-MS analysis showed that 32 components were isolated from MJEO, with linalool being the most abundant. The results of the antioxidant activity assay demonstrated that MJEO has an effective ability to scavenge free radicals. The above research findings provide an important theoretical basis for the high value utilization of medicinal plant resources. The application of MAHD technology not only significantly enhanced the extraction efficiency of MJEO but also offered scientific support for the comprehensive utilization of Maojian tea resources and the high-quality development of the tea industry, possessing both significant academic value and practical significance.