Two-dimensional transition metal dichalcogenides (TMDs) are a new type of two-dimensional materials after graphene. Due to their unique physical and chemical properties, much attention has been attracted in semiconductors, optoelectronic materials, energy storage, and catalytic hydrogen production. Chemical vapor deposition (CVD) is currently one of the processes suitable for realizing large-scale preparation of two-dimensional materials. Due to the highly controllable parameters of CVD process, it has great advantages in the preparation of two-dimension materials. In this paper, the recent research progress on preparation of TMDs by CVD is reviewed, and the influence of various factors on the growth and final morphology of the products in CVD preparation process, including precursors, temperature, substrate, auxiliaries, pressure and carrier gas are discussed. Some improved CVD processes are listed and their characteristics are also summarized. Finally, challenges and prospects for the development of TMDs prepared by CVD are discussed.