The invention relates to a chemical method for inducing seashells to spawn, which is characterized in that before spawning, according to the quantity of the breeding shells of the seashells, the breeding shells are concentrated in a container, and seawater is added; then vitamin B1, B12 and vitamin C are added in the seawater, and the concentration ranges thereof in the seawater are 0.01g-0.02g / l, 0.05mg-0.1mg / l and 0.01g-0.02g / l respectively; air charging is carried out to the seawater continuously; after soaking for 30-60 minutes, the breeding shells are transmitted into the seawater of a spawning pool for carrying out spawning; after 30-40 minutes, the breeding shells begin spawning. The vitamins can not only supplement nutrient for the breeding shells, but also promote the ovum to mature and grow, have little stimulation for the survival of the breeding shells, can lower the danger for the seashells and the ovum, can also promote the zygote to mature and grow quickly, improve the fecundation rate and the hatch rate of the zygote and also improve the success rate of the seedling, meanwhile, the health of the operator can not be influenced.