As China experiences a deceleration in infrastructure construction and the gradual aging of existing buildings, the impending demand for the repair and reinforcement of engineered structures is poised to surge, accompanied by a growing necessity for special repair materials. The cost-effectiveness and performance optimization of magnesium phosphate cement (MPC), a rapid repair and reinforcement material, are key considerations for its practical application. The incorporation of industrial solid waste is considered an effective means to regulate the cost and performance of MPC. Recent studies have demonstrated the potential for industrial solid waste, such as fly ash, to be utilized in the fabrication of MPC, with the objective of enhancing its performance and reducing its cost. Numerous reviews have been published on the subject of MPC development. However, the majority of these reviews have concentrated on the fundamental mechanisms and application domains of MPC, with comparatively fewer studies addressing the mechanisms, reactivity, physical stacking effects, and chemical bonding principles of solid wastes within MPC system. This review is innovative in that it investigates the research progress of solid waste-modified MPC from two perspectives: performance and mechanism, based on the principle of chemical bonding. It discusses the working, mechanical properties and mechanism of solid waste-modified MPC, and comprehensively evaluates the current situation. Finally, it summarizes existing research and puts forward future research directions with a view to improving the performance of MPC, reducing the cost, and promoting its wide application in practical engineering.