The invention relates to the field of spraying and granulating machines, in particular to a spray-drying and granulating method and a device thereof. The spray-drying and granulating device adopts thetechnical scheme that the spray-drying and granulating device comprises a drying tower, wherein the upper end of the drying tower is respectively connected with an atomizing spray head and a heatingand air delivery device; the atomizing spray head is connected with a material liquid pipe; the lower end of the drying tower is connected with a material discharge conical hopper; a driving mechanismis arranged on the drying tower, an output shaft of the driving mechanism is connected with a rotary shaft, the rotary shaft is connected with the side wall of the drying tower through a bearing, theother end of the rotary shaft is fixedly connected with a rotary disc, a support rod is fixedly arranged at the edge of the rotary disc, the other end of the support rod is connected with a connecting rod through a bearing, a lifting rod is hinged to the other end of the connecting rod, and a push plate is fixedly arranged at the other end of the lifting rod, and is arranged in the drying tower.The spray-drying and granulating method and the device thereof have the advantages that the atomized material can be uniformly and quickly heated; the problem of nonuniformity of particles due to nonuniform heating of the atomized material in the existing spraying and granulating machine is solved.