A synergistic fungicide composition, a formulation method and a use thereof are provided. The composition contains two active components A and B, where the active component A is benziothiazolinone, the active component B is one selected from dithianon, dimethomorph, iprodione and epoxiconazol, and the weight ratio of the two components is 1:50 to 50:1, and preferably 1:30 to 30:1. Test results show that, the fungicide composition has a significant synergistic effect, and more importantly, the application amount and the use-cost are reduced. The fungicide composition is effective in preventing and treating certain fungal diseases of crops such as food crops, vegetables and fruits.