The invention provides a high-density cotton seed sowing machine being convenient to shape. The high-density cotton seed sowing machine comprises a frame, and a fertilizing device mounted in the front of the frame and used for fertilizing, wherein fertilizing colters used for forming fertilizing grooves are mounted at the bottom of the fertilizing device; sowing devices are arranged on the frame and behind the fertilizing device; each sowing device comprises a furrow opener arranged at the bottom of the frame and used for forming seed grooves, and a seed box arranged above the frame and used for accommodating cotton seeds; seed-discharging devices used for discharging the cotton seeds are arranged in the seed discharging openings in the bottoms of the seed boxes; shaping springs used for extending along with sowing terrain are mounted above the furrow openers; the extending of the shaping springs drives the furrow openers to float up and down; a four-connecting rod shaping device capable of swinging along with the terrain is connected to the front end of the sowing device. The seed sowing machine adopts a double-shaping device, and can sow according to characteristics of the terrain better, so as to improve the consistency between sowing stability and sowing depth.