The invention discloses a rainwater collecting system and relates to a rainwater collecting technology. The rainwater collecting system comprises a rainwater collector, a rainwater storage bucket and a filtering device. The rainwater collector is in a hopper shape, and a water outlet is formed in the bottom of the rainwater collector. A water inlet is formed in the upper portion of the rainwater storage bucket, and a water outlet is formed in the lower portion of the rainwater storage bucket. The filtering device is arranged between the water inlet and the water outlet of the rainwater storage bucket. A connecting pipe is arranged between the water outlet of the rainwater collector and the water inlet of the rainwater storage bucket. The rainwater collecting system not only can collect rainwater in the rainwater collector and enable the rainwater to be conveyed to the rainwater storage bucket through the connecting pipe, but also can filter the rainwater through the filtering device and meet different requirements of water using. The hopper-shaped rainwater collector can enable the collecting area to be increased, the collecting effect is improved, the structure is simple, cost is low, the rainwater is convenient to collect and use, lacks of water resources can be effectively relieved, energy is saved, and the environment is protected.