The edges of speckles in traditional camouflage patterns is smooth and clear which is disadvantage to blend with the background with broken speckles. The edges of digital camouflage are ambiguous and broken. Big speckles can be segmented effectively at short range observation. Spatial color mixture is formed at long distance observation and the effect of camouflage is enhanced greatly. So the digital camouflage is one of the most important parts in camouflage design in recent years. The important step of digital copy camouflage design is from the main color speckle in background to the generation of digital camouflage. According to the spatial color mixture principle, a probability model of digital camouflage speckle distribution is introduced so as to quantify the distribution of digital camouflage unit. The generation method from main color speckles in background to digital camouflage patterns is designed. Incorporating with MATLAB image processing technology and probability distribution models, digital camouflage patterns are generated through programming. The result shows that the digital camouflage patterns with broken edges and good spatial color mixture effect can be generated with the method. And a new idea is provided for the design of digital copy camouflage.