The invention provides a variable-diameter sliding sleeve switch. The variable-diameter sliding sleeve switch comprises an upper joint, a lower joint and a sliding sleeve which can slide in the upper joint and the lower joint, wherein the upper joint and the lower joint are hermetically and fixedly connected, the upper joint is sequentially provided with a first liquid outlet and a second liquid outlet from top to bottom, the sliding sleeve and the upper joint are connected through a sliding sleeve shear pin and the sliding sleeve is located at the upper end of the first liquid outlet; an upper sealing ring, a lower sealing ring, a bushing and an elastic piece are sequentially sheathed at the middle part of the upper joint, the upper sealing ring is fixedly connected with the upper joint, the upper sealing ring is in sealed contact with the lower sealing ring, the sealed contact position is located at an exit of the second liquid outlet, the lower sealing ring is fixedly connected with the bushing, the bushing is fixedly connected with the elastic piece and the elastic piece is fixedly connected with the lower joint. The variable-diameter sliding sleeve switch has the advantages that the structure is simple, the variable-diameter sliding sleeve switch is convenient to use, the magnitude of the caliber of the liquid outlet can be changed according to different pressure during use, and a great amount of sand fracturing construction demands are satisfied.