The invention discloses a rainfall test box, comprising a box body, a transparent glass door, an air inlet cylinder, a first transparent glass plate, a first scale line, a material mixing cylinder, amaterial mixing motor, a burdening cylinder, a second transparent glass plate, an air inlet fan, a filtering plate, a spray component, a leakage plate, a water inlet, a stirring rod and a discharge valve. The rainfall test box disclosed by the invention is provided with the material mixing cylinder and the burdening cylinder, and is provided with the first scale line and a second scale line, so that matching simulation can be performed according to the pH of the rainwater, the simulation effect is improved, the rainfall test box is provided with the spray component to perform movable spray, sothat multi-angle movable spray can be performed, the rainwater spray state in a natural state can be simulated, the simulation state is diversified, the simulation effect is good, the rainfall test box is provided with the air inlet fan to achieve a cooperative simulation state of the wind power of the spray, so that the test effect is improved, and the rainfall test box is provided with a transfer water pump to achieve the self-circulation of the water in the test box, so that a lot of water resources are saved under a long-term experiment, and long-term continuous simulation can be performed.