The invention provides an axisymmetric shrinking and expanding nozzle of a single-actuation system, which is mainly composed of a cylinder (1), an actuating cylinder (2), a pull rod (4), a convergence adjustment plate (5), and an expansion adjustment plate (6 ), the first bracket (7), the outer cover (8), the expansion sealing plate (9), the thin-walled swirl center body (10), the second bracket (11) and the convergence sealing plate (12). Among them, the cylinder body (1) is used as the supporting member of the entire nozzle; the actuator (2), the pull rod (4) and the convergence adjustment plate (5) are used as the throat area adjustment mechanism, and at the same time drive the expansion adjustment plate (6) to move, The outlet area can be changed according to a fixed rule; the thin-wall swirl center body (10) is used for shielding the front-end component. The invention has the advantages that the adjustment of the throat area and the outlet area is realized through a set of actuating system, and the nozzle has good stealth ability without affecting the adjustment range of the throat area, and has a simple structure and high reliability.