The invention discloses a dehydrator for an umbrella. The dehydrator comprises a box body part, a dehydration device and a transmission device, wherein the box body part is composed of an upper box body, a lower box body and a side plate; the dehydration device is mounted in the upper box body; a water storage tank is arranged in the lower box body; two driving modes namely a manual driving mode and a pedal driving mode are provided through the transmission device. The dehydrator is suitable for different crowds. In addition, removed rainwater can be recycled by the water storage tank, the dehydration efficiency is high, the application range is wide and the dehydrator can be widely applied to occasions such as buses, shopping malls, hotels and schools.