Outdoor building rainwater collecting device applied to building design

The utility model relates to the technical field of building design, in particular to an outdoor building rainwater collecting device applied to building design, which comprises a collecting box, a filter assembly is arranged in the collecting box, and the filter assembly comprises a fixed cylinder, a threaded rod, a filter screen and a motor; a fixed cylinder is rotatably connected in the collecting box, a threaded rod is in threaded connection in the fixed cylinder, a filter screen is fixedly arranged at the top of the threaded rod, the outer side of the filter screen abuts against the inner wall of the collecting box, a motor is installed at the bottom of the collecting box, and the output end of the motor is connected with the fixed cylinder. After rainwater collection is completed, a motor drives a fixing cylinder to rotate, a guide rod and a fixing block are in sliding connection to play a limiting role, when the fixing cylinder rotates, a threaded rod drives a filter screen to ascend, the filter screen