The invention discloses a rotary disassembling machine for an antitank rocket projectile and a using method for the rotary disassembling machine, and belongs to the technical field of safeguard of antitank rocket projectiles. The rotary disassembling machine comprises a machine body. The machine body is provided with a power mechanism, a rotating mechanism and a fixed mechanism. The power mechanism and the rotating mechanism are connected through a transmission mechanism. The rotating mechanism or the fixed mechanism is connected with a moving mechanism. The moving direction of the moving mechanism is collinear with the axial direction of the rotating mechanism. A locking mechanism is arranged on the rotating mechanism. The rotary disassembling machine is simple in structure, convenient to use and capable of disassembling the antitank rocket projectile in a nondestructive manner; operators are prevented from making direct contact with dangerous objects; and the safety, the reliability and the working efficiency of disassembling are improved.