The invention provides a telescopic spontoon, and relates to the technical field of antiriot equipment. The telescopic spontoon comprises an outer tube, a medium tube, a rear tube, a medium tube locking mechanism, a rear tube locking mechanism, an unlocking mechanism, and a pounding head. The medium tube locking mechanism comprises a first drum butterfly, a second drum butterfly, and a pair of drum butterfly springs. The first drum butterfly is slidably cooperated with a first drum butterfly sliding groove. The side of the first drum butterfly, facing a medium tube cavity, is provided with a first drum butterfly lug. The central position of the first drum butterfly lug is provided with a first drum butterfly unlocking hole. The right side of the first drum butterfly is provided with a first drum butterfly anti-shock groove. One side of the second drum butterfly, facing the medium tube cavity, is provided with a second drum butterfly lug. The second drum butterfly lug is provided with a second drum butterfly unlocking hole on the position corresponding to the first drum butterfly unlocking hole. The right side of the second drum butterfly is provided with a second drum butterfly anti-shock groove. The pair of drum butterfly springs are supported between the first drum butterfly and the second drum butterfly. The left end of the medium tube and the right end of the outer tube are ensured to be reliably locked, and the left end of the rear tube and the right end of the medium tube can also be reliably locked.