The 4SY-1 rape windrower is mainly composed of frame, circulating cutter, two-way symmetric reeling mechanism, and transmission mechanism, etc. During the work, the rape stalks are cut by the circulating cutter driven by the symmetrical reel mechanism on the left and right sides, and pushed and squeezed from both sides to the laying channel to achieve two-way symmetric reeling and back-side laying. The stalks are laid in a lap at the beginning and end. The parameters of cutting blade edge were optimized to ensure the reliability of the circulating cutter during the cutting process. The two-way symmetric reeling mechanism for intermediate laying was designed by using the principle of manual spreading, and the main structural dimensions of the reeling mechanism were determined. The field test results show that the rape laying angle is 11.48°, the angle difference is 6.64°, the average laying height of rape is 562.7 mm, and the average laying width is 955.6 mm, at the working speed of 0.8 m/s, cutting width of 1 m and planting density of 225 000 plants/hm2. It is found that the rape is laid in the field in the way of first and last lap, and the cutting and reeling device of the rape windrower can complete the field rape cutting, reeling and laying operation in the field at one time effectively.