Because of the drives reliably and has a simple structure of chain transmission,it is applied widely in agricultural machinery.For example,the chain bucket filter is applied in recirculating system in aquaculture.The key part of chain bucket filter is sprocket which often works in harsh conditions,complex load or other situation.This circumstance can make the tooth worn and failed to work.To increase the life and reduce the stress concentration of sprocket,by using the platform of Pro/Engineer,a three-dimensional model of the sprocket is built,and the dynamics analysis and structure optimization are carried out by using Pro/E Mechanica,and at the same time to reduce the weight of sprocket,the force of sprocket is distributed well and the concentration of stress and deformation is reduced.The global sensitive analysis of sprocket shows that the increase of the radius of addendum has weakened,the growth of the maximal stress and the maximal stress has decreased with the increase of flange diameter.Finally,an optimal design for two important parameters is carried out based on the minimum quality of sprocket and find optimization within reasonable limitations:When the tooth top arc diameter and flange diameters is 14 mm and 54.953 2mm respectively,the minimum quality of the model is 3.437 6kg and the quality of the model has decreased by 4.48%.