Garden water self-purifying circulating system and method

The invention discloses a garden water self-purifying circulating system. The garden water self-purifying circulating system comprises inclined ramps at both sides, wherein spraying devices and silt discharge ports are arranged at the high locations of the two ramps; a catchpit is arranged at the low locations of the two ramps; a filtering device with a first filtering cage and a second filteringcage is arranged at a mouth of the catchpit; the lower locations of the ramps at the two sides are communicated with the side edges of the first filter cage through connecting pipes; the bottom outputof the catchpit is connected with a silt sterilizing tank through a first silt suction pump; the output of the silt sterilizing tank is connected with a silt discharge port through a second silt suction pump; the upper part of the catchpit is sequentially connected with a conditioning tank, an anaerobic tank, an aerobic tank and a secondary settling tank through liquid level pipes; a purified water port at the upper part