Mechanoluminescence (ML), which refers to the light emission in response to mechanical stimuli, presents significant potential for stress sensing, anti-counterfeiting measures, and structural health monitoring. Currently, most ML materials are typically based on complex compositions or multiphase systems. In this study, we present that simple magnesium oxide (MgO) serves as an excellent host for producing self-recoverable near-infrared ML through doping Cr³⁺ ions. We found that high sintering temperature significantly enhanced the ML intensity of MgO:Cr³⁺, which is ascribed to high equilibrium concentrations of charge carriers and defects, as confirmed by DFT calculations. The ML properties were further improved by rational optimization of dopant concentration, annealing atmosphere, Ln³⁺ co-doping, and Zn²⁺/Al³⁺ alloying. Additionally, the nanoplate-like MgO:Cr³⁺, which exhibits exceptional ML film …