In recent years, 2D metal dichalcogenides (2DMDs, MX2: M = Mo, W, Re, Nb; X = S, Se, Te, etc.) have intrigued significant attention due to diverse properties such as tunable bandgaps, valley polarization, showing highly promising applications in electronics and optoelectronics. For practical applications, large-scale synthesis of 2DMDs is indispensible, and thus becomes an urgent research question. In this review, the latest methods of synthesizing large-scale 2DMDs are introduced, such as mechanical exfoliation, liquid phase method and chemical vapor deposition (CVD). Besides, CVD process are classified into the following parts: direct growth via vapor phase deposition, chalcogenization of the deposited films of metal precursors on the substrate, synthesis of large-scale 2DMDs on the treated substrate and on the molten substrate. Finally, a perspective is provided for this exciting and fast-developed field at the future, which points out that the major existing obstacles are the limited domain size, the crystallinity, layer controllability, and universality of the synthesis methods, which prevent the practical applications.