Abstract：A new method of some linear objects tracking such as the runway being changed to tracking of the feature point is presented based on Hough transform during the stable-falling of the sub-muniton. Given all the case of each parameter’s decoupling

the parameters of the line in Hough space have been estimated and predicted with the methods of Kalman filtering. In order to establish the relative position between the runway and sub-munition

some modificative processing in equation for predicting the state of objects’ contrail are conducted combining some data information of the current image when considering the influence of the detector’s spinning with sub-munition. In the instance of small perturbation

a new processing data is established based on the theory of parachute-munition’s dynamic analysis in order to obtain the curve of D0 which would ascertain the relative position of sub-munition and runway. All processing data shows that this method has high efficiency and good stability

and reduces the quantity of calculation to some extent. Experiment results show the error of estimation is small and it can meet the general object requirement.