The fumigant has been approved by the World Health Organization for use in grain storage, targeting the eradication of pests in areas where grain is stored or transported to reduce insect and mold activities, thereby minimizing storage losses. Phosphine is featured by its economic viability, application readibility, rapid diffusion, and lack of residue, making it advantageous for comprehensive pest control. It demonstrates high efficacy against various harmful organisms in storage, making it one of major fumigants worldwide. However, the elimination of some fumigants has increased dependence on phosphine. The lack of standardized guidance and inappropriate use of phosphine have led to severe resistance among stored grain pests, posing a threat to the effectiveness and sustainability of phosphine treatment. This paper provides a comprehensive review of the current status and trends of phosphine resistance in stored grain pests on the global. It analyzes the genetic basis of resistance, focusing on respiratory and cuticle-related gene expression and detoxification enzyme mechanisms. A comparison of four resistance detection methods—FAO, discriminating does bioassay, rapid knockdown, and molecular identification—is rendered. The study explores key strategies for resistance management, including optimization of fumigation protocols, laboratory and field validations, and application recommendations. The aim is to offer reference information for the scientific and rational use of phosphine and the development of alternative pest control methods in the future.