The invention discloses a wet green plant cutting method for repairing loess wound slopes. The method includes taking a wet cutting device consisting of a backpack type high-pressure water tank and awet cuttage device in non-precipitation weather, and injecting nutrient water containing nutrient elements required for plant growth into the backpack type high-pressure water tank; placing the root of the nursery stock in a trunk groove, placing the tip of the green plant root in a pointed cone head groove, sending the root of the nursery stock into soil through the wet cuttage device, and injecting water around the root of the nursery stock to provide initial water and nutrients for the root of the plant, and preventing the loess wound surface slope surface from being damaged again due to hole excavation; and after green planting is completed, arranging a Y-shaped interceptor on the back runoff side of each green plant. During precipitation, the interceptors intercept the precipitation flowing downwards along the slope surface and introduce the intercepted precipitation into the root of the green plant in the soil through a diversion pipe, which can not only prevent the rain from scouring the slope, ensure the stability of the slope, but also provide water and nutrition for the green plant and enhance the growth of the green plant at the later stage.