Building rainwater collection and utilization device

The utility model belongs to a rainwater collection and utilization device, and particularly relates to a building rainwater collection and utilization device. The building rainwater collection and utilization device solves the problems that in the existing rainwater collection process, pollution is prone to occurring, and rainwater storage and rainwater utilization are very inconvenient. The building rainwater collection and utilization device comprises a rainwater collection tray (1), a water pipe (2), a water storage tank (3), a first first-level drain pipe (4), a second first-level drain pipe (5), a filter (6), a plurality of first second-level drain pipes (8) and a plurality of second second-level drain pipes (8). The concave arc surface of the rainwater collection tray (1) is communicated with one end of the water pipe (2), the other end of the water pipe (2) is communicated with the top end of the water storage tank (3), and the bottom end of the water storage tank (3) is communicated with one end of t