The utility model discloses a rotary locking piece and a hot melting tool, the rotary locking piece is used for locking a rodlike body and comprises a locking piece body, a rodlike body channel with an opening larger than the cross section size of the rodlike body is arranged in the locking piece body, rotating shaft parts are arranged on the locking piece body and located on the two sides of the rodlike body channel, and the rodlike body channel is communicated with the rotating shaft parts. And the inner surface of the rod body channel is provided with a compression locking surface which is matched with the surface of the rod-shaped body for locking in an inclined state. According to the utility model, the pressing locking surface is pressed on the surface of the rod-shaped body, so that the damage to the surface of the rod-shaped body can be effectively reduced, and the breakage of the rod-shaped body is avoided; and double-side locking can be achieved through the double pressing locking faces, the locking effect of the rod-shaped body is better, glue discharging is more stable, deformation, damage and breakage of the rod-shaped body can be avoided through vertical matching, and a user does not need to worry about damage to the rod-shaped body due to excessive pressing any more.