The utility model relates to a reflective membrane collection rain device, its characteristics are: it includes rainwater collecting groove, water diversion groove and water tank, rainwater collecting groove is for adopting the reflective membrane to lay to the concave groove of both sides ridge platform along the furrow, and rainwater collecting groove's a mouth limit is fixed and is fixed at the bottom of the furrow in ridge bench, bottom surface, and the reflective membrane one end that founds rainwater collecting groove is upwards erect and is formed the end cap, the other end opens, the recess that water diversion groove dug out the horizontal groove ditch for the edge of a field and adopted the reflective membrane to lay along the horizontal groove ditch, water diversion groove are located the unlimited below of holding of rainwater collecting groove, and water diversion groove's a mouth limit is fixed and is fixed at the bottom of the horizontal groove ditch in subaerial, bottom surface, and structure water diversion groove's reflective membrane one end is upwards erect and is formed end cap, the unlimited conduct irrigating gate of the other end, the below that water diversion groove opened the end is arranged in to the water tank, and the rainwater that the irrigating gate flows is accepted to the water inlet of water tank. Be fit for the farmland first part rain in mountain area or halfway up the hill district, have simple structure, implementation with low costs, easy, convenient operation, increase photosynthesis, laborsaving, advantage such as the range of application is wide saves labour.