The invention discloses a missile rudder piece tool fixture. The missile rudder piece tool fixture comprises a bottom plate, a stop block, a trapezoid block and an air cylinder. The bottom plate comprises a first part and a second part, the second part is arranged on the right side of the first part and is lower than the first part, and the upper surface of the first part is provided with a tenon-shaped groove which completely penetrates through the right side of the first part and does not penetrate through the left side of the first part; the stop block is arranged in the tenon-shaped groove; a spring A is arranged between the stop block and the left side of the first part in the horizontal direction; a trapezoid cavity is formed in the position, close to the lower portion of the right end of the tenon-shaped groove, of the interior of the first part; the trapezoid block is placed in the trapezoid cavity; a spring B is fixed under the trapezoid block and is connected to a first part body in the bevel direction of the trapezoid cavity; a push plate is arranged on the right side of the trapezoid block and penetrates through the first part through a push rod to be connected with the air cylinder; the air cylinder is arranged on the upper surface of the second part; and a through hole is formed in the position, corresponding to the push rod, of the first part. The missile rudder piece tool fixture has the beneficial effects that the automation degree and the production efficiency are high, and the labor intensity is relieved.