The invention relates to an adjustable horizontal tail, and belongs to the technical field of the structure design of an airplane. The adjustable horizontal tail comprises a horizontal tail wallboard, a front beam, a middle beam, a wing rib, a front beam connector, a left side lifting rudder, a rear beam connector, a rear beam, a right side lifting rudder, a drive connector, a hinge connector, a deformable rectifying wrapper, a vertical tail, a vertical tail rear beam and a drive pull rod; a left horizontal tail and a right horizontal tail are of an integral part, a bending moment and a torque of a pneumatic load acting on the horizontal tail can be internally balanced, the requirement for the force transfer of a vertical tail connecting piece can be lowered, smoothness in force transfer can be realized, and the structural weight can be saved; the adjusting mechanism is simple, the control is stable, and the weight is small. The pneumatic appearance can be prevented from being damaged due to the motion requirement.