A method for preparing a sword bean tea is provided. In the method, a washed sword bean or a pod of the sword bean is cut into a predetermined size. The sword bean or the pod of the sword bean is dried at 30° C. to 40° C., for 24 hours to 72 hours. The sword bean or the pod of the sword be is roasted at 250° C. to 400° C. for 10 min to 30 min. The sword bean or the pod of the sword bean is left at 70° C. to 100° C. for 3 min to 10 min, and the sword bean or the pod of the sword bean is then stirred. The leaving and the stirring are alternately and repetitively performed five times. The sword bean or the pod of the sword bean is roasted at 180° C. to 200° C. for 3 min to 5 min.
