The invention discloses a rainwater collection device and method. The rainwater collection device comprises a reservoir, a rotary disc arranged on the reservoir, a vertical barrel arranged on the rotary disc, a filter screen arranged at the upper end of the vertical barrel and with an upward opening, a water collection cover arranged at the upper end of the vertical barrel, a vertical pipe extending above the opening and with closed upper end and lower end, a plurality of nozzles arranged on the vertical pipe and a solar cell panel arranged on the vertical barrel. A storage battery and a controller are further included, the rotary disc is slidably connected with a guide rail arranged on the reservoir, the cross section of the vertical barrel is rectangle, the water collection cover comprises waterproof cloth in a rectangular pyramid shape and a plurality of rectangular annular supporting frames arranged on the inner side and the upper edge of the waterproof cloth, and two air cylindersarranged on the opposite side surfaces of the vertical barrel are separately connected with the supporting frames on the edge of the water collection cover through connecting rods. The rainwater collection device and method have the characteristics of larger water collection area and high rainwater collection efficiency.