In view of the insufficient theoretical research on the existing cotton bale wrapping technology and the issues include frequent blockage in the film feeding process and poor edging effect in domestic round baler cotton picker, a point-braking type film wrapping system was designed. The system mainly consisted of film feeding device, point-braking tensioning device, and control unit. By studying the film wrapping mechanism of cotton round bales, the necessary conditions for film feeding, the effective area of successful film feeding on the guide device, and the boundary conditions for the formation of edge wrapping at the ends of the cotton package were theoretically analyzed. A three-factors, three-levels quadratic regression orthogonal test was conducted with packing belt speed, point-braking cycle, the ratio of braking time to film feeding time (referred to as the braking ratio) as the test factors, and the average edge width of the cotton package and the average cotton bale density as the test indexes. A regression model was established to analyze the impact of each factor on the film wrapping system. The optimized working parameters was as follows: packing belt speed of 156r/min, point-braking cycle of 1200ms and braking ratio of 1.2. The combination of these parameters was tested in the field, the average edge width was 160mm and the average cotton bale density was 193kg/m3. The experimental results differed from the theoretically optimized values by less than 5%. The research results can provide reference for the design of cotton packaging and harvesting machinery.