The invention discloses a weeding combination, which is a duality weeding combination consisting of the effective components of compound (a) and compound (b). The compound (a) is atrazine (2-chlorine-4-ethylamino-6-isopropylamino-1, 3, 5-triazine); the compound(b) is a compound with the structure of formula (I), wherein, R is Na or K, and X is Br or I; the weight ratio of compound (a) and compound (b) is 1: 0.08-8. The invention further discloses an application of the weeding combination, i.e., the weeding combination is used for preventing and eliminating the ruderal weeds of gramineae and broadleaf in farmlands of corn, sugar cane, etc., after seedling. The prevention effect of the combination is better than the activity in the separate use of herbicides, and the combination can bring surprising enhancing effect. Additionally, the combination has positive effect on the following aspects such as expanding the scope of prevention and cure of ruderal weeds, reducing the times of application and lowering the cost of application, etc. The combination of the invention is safe to the growth of the existing corn and later crops.