Mountain slope supporting device and method

The invention relates to the technical field of mountain slope supporting, and discloses a mountain slope supporting device and method.The mountain slope supporting device comprises a mountain slope, a fixing plate, a fixing anchor, a second steel pipe, a first steel pipe and a connecting steel bar, a water catchment hole is formed in the upper side face of the fixing plate, and a drainage hole is formed in the fixing plate; a filter screen is fixedly connected to the upper end of the inner wall of the water catchment hole, a geotechnical cloth layer is arranged on the inner wall of the lower end, close to the filter screen, of the water catchment hole, the lower end of an inner containing cavity of the water catchment hole is communicated with the drainage hole, a first channel is formed in the first steel pipe, a second channel is formed in the second steel pipe, and the end, away from the water catchment hole, of the drainage hole is communicated with the first channel. The interior of the channel II is co