Efficient particle filter based track before detect (EPF-TBD) method based on object existence probability slope

The present invention provides an efficient particle filter based track before detect (EPF-TBD) method based on an object existence probability slope. According to object existence probabilities, existence judgment is carried out. At an initial moment, an existing probability of an object at a current moment and a threshold value are compared for judgment; if the existing probability of the object at the current moment is larger than the threshold value, the object at the current moment is judged to exist, and the object at the current moment is judged to not exist otherwise; at other moments apart from the initial moment, a variation between the existence probability of the object at the current moment and that of the object at the last moment is judged if to be larger than a threshold value, if so, an existence judgment result of the object at the current moment is different from that of the object at the last moment, and the existence judgment result of the object at the current moment is the same as that of the object at the last moment otherwise. With adoption of the EPF-TBD method provided by the present invention, missing detection and false alarm problems can be effectively relieved, and the detection performance is excellent.