Interference and anti-interference are two opposite and important issues in visual tracking.Occlusion interference can disguise the features of a target and can also be used as an effective benchmark to determine whether a tracking algorithm is reliable.In this paper,we proposed an inner Particle Swarm Optimization(PSO)algorithm to locate the optimal occlusion strategy under different tracking conditions and to identify the most effective occlusion positions and direction of movement to allow a target to evade tracking.This algorithm improved the standard PSO process in three ways.First,it introduced a death process,which greatly reduced the time cost of optimization.Second,it used statistical data to determine the fitness value of the particles so that the fitness more accurately described the tracking.Third,the algorithm could avoid being trapped in local optima,as the fitness changes with time.Experimental results showed that this algorithm was able to identify a global optimal occlusion strategy that can disturb the tracking machine with 86.8%probability over more than 10 000 tracking processes.In addition,it reduced the time cost by approximately 80%,compared with conventional PSO algorithms. Interference and anti-interference are two opposite and important issues in visual tracking. Occlusion interference can disguise the features of a target and can also be used as an effective benchmark to determine whether a tracking algorithm is reliable. This paper, we proposed an inner Particle Swarm Optimization (PSO) algorithm to locate the optimal occlusion strategy under different tracking conditions and to identify the most effective occlusion positions and direction of movement to allow a target to evade tracking. This algorithm improved the standard PSO process in three ways. First, it introduced a death process, which greatly reduced the time cost of optimization .Second, it used statistical data to determine the fitness value of the particles so that the fitness more accurately said the tracking.Third, the algorithm could avoid being trapped in local optima , as the fitness changes with time. Experimental results showed this algorithm was able to identify a global optimal occl usion strategy that can disturb the tracking machine with 86.8% probability over more than 10 000 tracking processes. addition, it reduced the time cost by about 80%, compared with conventional PSO algorithms.