A new composite vibrating mode is presented in this paper. Modeling and dynamic analysis are studied according to two-degree-of-freedom systems theory. The effects of vibration parameters, including swing angle, swing frequency, vibrating direction angle, and translation frequency, on the screening efficiency were researched by means of experiment research over a new laboratory-scale composite vibrating screen which is designed based on the new composite vibrating mode. The results are analysed in terms of curves and fitting equations. Compared to the translation mode and swing mode, the screening performance of the new composite vibrating mode, both in screening efficiency and in processing capacity, is significantly improved.