Abstract: Low-melting-temperature poly(aryl ether ketone) (LM PAEK) and its composites have garnered significant attention in the field of high-performance thermoplastic composites due to their exceptional formability, mechanical properties, and chemical stability. This paper systematically describes the molecular structure characteristics of LM PAEK and highlights its unique advantages in terms of processability, crystallization behavior, and mechanical properties. Furthermore, it compares the performance differences between LM PAEK and traditional poly(aryl ether ketone) (PAEK) resins, such as poly(ether ether ketone) (PEEK) and poly(ether ketone ketone) (PEKK). The effect of low melting temperature and melting viscosity of LM PAEK on the efficiency of composite molding was analyzed. Additionally, this study discusses the research progress on bulk crystallization effects, induced crystallization behavior, and their impacts on interface properties, fracture toughness, impact properties, and high-temperature stability of composite materials. These discussions provide novel insights for optimizing composite properties based on its excellent processability and sustainable development potential. Moreover, it reveals the application value of LM PAEK in manufacturing technology field like automatic laying in situ forming, 3D printing and aviation main bearing structures. These findings serve as a reference for future research endeavors and technological advancements.