NOVELTY - Minimally invasive excavating multi-medium subsurface infiltration filter comprises an auxiliary device buried underground, a water distribution device and a water collection device. The auxiliary device comprises calcium carbonate particles filled between two layers of wire mesh at top and bottom. The calcium carbonate particles are obtained by mixing calcium carbonate powder with hot melt adhesive, preparing into hollow spherical calcium carbonate particles, injecting methanol solution and sealing. A non-woven geotextile is set between the calcium carbonate particles and wire mesh layer.    USE - The minimally invasive excavating multi-medium subsurface infiltration filter useful for processing irrigation water (claimed).    DETAILED DESCRIPTION - Minimally invasive excavating multi-medium subsurface infiltration filter comprises an auxiliary device buried underground, a water distribution device and a water collection device. The auxiliary device comprises calcium carbonate particles filled between two layers of wire mesh at top and bottom of the auxiliary device. The calcium carbonate particles are obtained by mixing calcium carbonate powder with hot melt adhesive at room temperature and preparing into hollow spherical calcium carbonate particles, and injecting methanol solution and sealing. The outer wall thickness of calcium carbonate particles is 2-30 mm. The mass ratio of calcium carbonate and methanol is 15:8. A non-woven geotextile is placed between the calcium carbonate particles and wire mesh layer. The water distribution device comprises multiple cloth water tanks, where each cloth water tank is surrounded with a layer of geomembrane having gravel with a diameter of 5-20 cm wrapped within the geomembrane, and a water distribution pipe. One end of the water distribution pipe is connected to an inlet pipe and the other end is closed. A water pore is opened on the pipe wall at every 10-20 cm, where the water pore has a diameter of 1-3 cm. The auxiliary device and water distribution device are set on top and bottom connected to each other. The water collection device is set on the lower part of cloth water device having a height difference with water distribution device of 2 m, where the between part of the device has soil. The water collection device comprises a water collection tank. Multiple water collection tanks are arranged vertical to the cloth water tank. The water collection tank is filled with gravels having a particle size of 5-30 cm. The gravel is fed with a slow release pesticide. The water collection pipe is parallely set with the water collection tank, and is set at a vertical line between two cloth water tanks. One end of the distribution water tube is connected to corresponding sealed end of the water inlet tube. The other end of the tube is connected close to the water outlet tube. The cloth water tank and sealed water pipe are provided with a slope. The gradient of cloth water tank and slope is 1:300 and the gradient of sealed water tube and slope is 1:200. The outlet pipe is connected to the water collection tank. The water collection tank is set with a nitrate concentration detector, heating device and sewage submersible sewage pump. The sewage submersible sewage pump is connected to a return tube. The return tube is buried in calcium carbonate particles of the auxiliary device.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the minimally invasive excavating multi-medium subsurface infiltration filter for processing irrigation water.