The development of efficient and affordable electrode materials is key to the construction of clean energy storage systems. Transition-metal chalcogenophosphates (TMPX₃, where TM represents Ni, Fe, Zn, V, Mn, Co, etc., and X denotes S, Se, or Te) are a promising class of two-dimensional (2D) layered materials with great potential for energy storage, photoelectrocatalysis, and electronic devices due to their unique electronic structure and tunable bandgap. In this review, we systematically summarise the latest research progress on TMPX₃ materials, adopting a pioneering multidimensional analysis framework to overcome the limitations of a unified single perspective. Firstly, we reveal the mechanisms of P–S bond anisotropy and TM coordination on the energy band structure from the atomic scale; secondly, through the comparative analysis of the existing preparation methods and regulation strategies, the optimised pathways for precise control of the number of layers and large-scale production are proposed. On this basis, we focus on the applications of TMPX₃ in photoelectrocatalysis and metal batteries, and elucidate the cross-scale correlation mechanism between its electronic/interfacial properties and macroscopic performance. Finally, the challenges and future opportunities of the material are presented, with the aim of providing valuable insights into the multi-field, precisely coupled design and energy storage applications of TMPX₃ materials.