The invention discloses a seed selecting device for soybean cultivation, and relates to the field of soybean cultivation. The seed selecting device comprises a bottom plate, wherein the top of the bottom plate is fixedly connected with a first box body and the second box body from left to right in sequence; one side of the first box body is fixedly connected with a transverse plate; the top of thetransverse plate is fixedly connected with a vertical plate and a first slide rail from left to right in sequence; the outer surface of the first slide rail is in sliding connection to a first slideblock; one side of the first slide block is fixedly connected with a first sieve plate; a plurality of first circular holes are formed inside the first sieve plate; and one end, away from the first slide block, of the first sieve plate penetrates through the first box body and extends to the other side of the first box body. The seed selecting device can perform seed selection quickly and conveniently in a soybean cultivation process, solves the problem that manual seed selection wastes time and labor, relieves burden of soybean cultivation staff, saves time, greatly improves seed selection efficiency, is good in seed selection effect, and guarantees soybean cultivation better and quicker.