The invention relates to the technical field of urban landscaping tree boxes, and discloses a rainwater purification tree box system. The rainwater purification tree box system comprises a rainwater purification tree box, a water inlet pipe, a water outlet pipe and a collecting well; and the rainwater purification tree box is communicated with the collecting well through the water inlet pipe. The rainwater purification tree box comprises an outer wall, a first cover plate and a base plate, wherein the first cover plate and the base plate are connected with the outer wall. A water purification layer and a second soil layer are sequentially arranged in the rainwater purification tree box from bottom to top; the water outlet end of the water inlet pipe penetrates the outer wall to be located in the water purification layer; the water inlet end of the water outlet pipe penetrates the outer wall to be located in the position, close to the base plate, of the water purification layer; the water outlet end of the water outlet pipe is located below the base plate. By means of the rainwater purification tree box system, rainwater is collected through the collecting well; the rainwater is effectively purified after being filtered by the rainwater purification tree box; the purified rainwater is recycled; and the rainwater purification tree box system has the beneficial effects of being good in purification effect and saving energy.