The physiological characteristics of aloe irrigated with brackish water and the relationship with ameliorative effects of silicon (Si) nutrition were studied. Results of cultivation and analysis showed that 2.0 mmol · L −1 added Si significantly alleviated growth inhibition and quality reduction of aloe under 100 mmol · L −1 NaCl stress; added Si significantly reduced Na + content while increased K + content and K + /Na + ratio of salt stressed aloe plant, especially absorption and translocation selectivity of aloe root to K + and Na + were promoted, and ion homeostasis of aloe plant was kept well. Results of cross-sectional X-ray energy dispersive spectrum microanalysis of aloe root and leaf further confirmed the above findings. One of the mechanisms of silicon was its improvement to activity of plasma membrane H + -ATPase, tonoplast membrane H + -ATPase and H + -pyrophosphates of aloe root under salt stress.