The utility model discloses a long stem grape caulerpa breeding device of vertical multilayer, including support, cultivation box, multiunit light source and bracket, the support have the multilayer to place the space through the plywood branch, cultivation box be top open box shape, place for every layer and set up a cultivation box in the space, every group light source is installed in every layer of cultivation box's top, provides illumination to cultivation box, cultivation box in be equipped with double -deck screen cloth, the bracket install in the below of support. The utility model discloses a vertical multilayer level is bred, and the light source that utilizes is adjustable artificial light source, does not rely on natural light source, to land resource's high -usage, and can setup in totally closed breed workshop, realized the full manual control to temperature, illumination and quality of water, it is little to the influence of the factors such as salinity, temperature andillumination change that cause because of season and weather, realized that the annual uninterruptedly of long stem grape caulerpa breeds, guarantees that the equilibrium of long stem grape caulerpais gone on the market, better economic benefits has.