An expandable baton, comprising: a plurality of sleeves, the plurality of sleeves being retractably disposed in sequence in a nesting manner; a positioning ring, the positioning ring being provided with an avoiding hole; a plurality of locking pieces, wherein the plurality of locking pieces are disposed at intervals around a peripheral side of the positioning ring and enclose an avoiding space, each of the plurality of locking pieces is connected with a sleeve, positioned on an inner side, of two adjacent sleeves in the plurality of sleeves, first axial ends of the plurality of locking pieces extend into the sleeve positioned on the inner side, and second axial ends of the plurality of locking pieces extend out of the sleeve positioned on the inner side and are stuck in a sleeve, positioned on an outer side, of the two adjacent sleeves to lock the two adjacent sleeves in an extending state; and an unlocking rod, wherein the unlocking rod is retractably disposed in the sleeve, positioned on the outer side, of the two adjacent sleeves, and when the unlocking rod extends into the avoiding space and, after passing through the avoiding hole, is pressed against the first axial ends of the plurality of locking pieces, the first axial ends of the plurality of locking pieces extend outwards under a pressing action of the unlocking rod, and the each of the plurality of locking pieces rotates by taking the positioning ring as a fulcrum, so that the second axial ends of the plurality of locking pieces are radially retracted and separated from the sleeve, positioned on the outer side, of the two adjacent sleeves and make the two adjacent sleeves in a free extension and retraction state. a plurality of sleeves, the plurality of sleeves being retractably disposed in sequence in a nesting manner; a positioning ring, the positioning ring being provided with an avoiding hole; a plurality of locking pieces, wherein the plurality of locking pieces are disposed at intervals around a peripheral side of the positioning ring and enclose an avoiding space, each of the plurality of locking pieces is connected with a sleeve, positioned on an inner side, of two adjacent sleeves in the plurality of sleeves, first axial ends of the plurality of locking pieces extend into the sleeve positioned on the inner side, and second axial ends of the plurality of locking pieces extend out of the sleeve positioned on the inner side and are stuck in a sleeve, positioned on an outer side, of the two adjacent sleeves to lock the two adjacent sleeves in an extending state; and an unlocking rod, wherein the unlocking rod is retractably disposed in the sleeve, positioned on the outer side, of the two adjacent sleeves, and when the unlocking rod extends into the avoiding space and, after passing through the avoiding hole, is pressed against the first axial ends of the plurality of locking pieces, the first axial ends of the plurality of locking pieces extend outwards under a pressing action of the unlocking rod, and the each of the plurality of locking pieces rotates by taking the positioning ring as a fulcrum, so that the second axial ends of the plurality of locking pieces are radially retracted and separated from the sleeve, positioned on the outer side, of the two adjacent sleeves and make the two adjacent sleeves in a free extension and retraction state.