The invention discloses a grooved formwork for pouring of a reinforced concrete base of a ballastless track, and relates to the technical field of ballastless track construction. The grooved formwork comprises a rectangular bottom plate. Vertical plates are arranged around the edges of the bottom plate, and the overall dimension of the bottom plate and the vertical plates is consistent with the dimension of a limiting groove in the reinforced concrete base. The bottom plate is provided with positioning devices matched with pre-drilled positioning holes in the surface of an engineering foundation, and is further provided with a height and levelness adjusting device used for adjusting the levelness and height of the bottom plate. The bottom plate is positioned through the positioning devices matched with the pre-drilled positioning holes in the surface of the engineering foundation, the levelness and height of the bottom plate are adjusted through the height and levelness adjusting device, operation steps are simplified, and construction quality is guaranteed. The grooved formwork has the advantages of being simple in structure, convenient to operate and capable of improving work efficiency, improving quality and lowering cost, and solves the problems that according to an existing grooved formwork for high speed railway bases, tools are heavy, work efficiency is low, engineering appearance quality is below standard, the labor intensity of workers is large, and construction cost is high.