Garden stagnant water drainage system

The invention discloses a garden stagnant water drainage system, comprising a drainage manhole cover and a sewer pipe. The drainage manhole cover comprises a drainage block, a buffer block and a mounting block, wherein the drainage block, the buffer block and the mounting block are concentric ring blocks, the buffer block is sleeved on the outside of the drainage block, the mounting block is sleeved on the outside of the buffer block, and the drainage block, the buffer block and the mounting block are closely adhered; the mounting block is provided with a first fixing block and a second fixingblock, the first fixing block is arranged on the outside of the mounting block, the second fixing block is arranged on the lower side of the mounting block, the first fixing block and the second fixing block are buried in the soil and fixed by the soil; A drainage hole is arranged on the drainage block, the drainage hole is evenly distributed on the drainage block, a rubber hose is arranged on the lower side of the drain