This paper mainly studies the basic model of fractal growing theory—DLA Diffusion Limited Aggregation Model. The method of computer simulation of DLA model is analyzed and realized. And the evolvement of the model is discussed. Multiple styles of aggression effect are figured out. Combing DLA model with the techniques and conclusions of simulating yarns and fabrics, this paper also uses double-side leaner DLA algorithm to generate the fluffy template. It makes texture synthesis with basic yarn image to simulate the fluffy effect. The algorithms studied in this paper are effective to reflect the fluffy characteristics of fancy yarns: irregularity, random diversity and local self-similarity.