Test mechanism unit, and vibration test system and method under engine follow-up thrust

The invention discloses a test mechanism unit which is used for simulating follow-up thrust generated in the flying process of a slender missile. Wherein the slender missile model comprises an aluminum bar and a test engine; in an initial state, the side columns are connected with the second end of the test engine through explosive bolts, the aluminum bar is bent, and the slender missile model is in a deformation state; after the explosive bolt is ignited and separated, the aluminum bar drives the test engine to move towards the other side of the supporting frame, and meanwhile the test engine is ignited to generate follow-up thrust. The invention further discloses a vibration test system and method under the engine follow-up thrust. The camera shooting unit obtains a motion image of the slender missile model; the vibration test unit obtains vibration data; and the thrust test unit is used for acquiring the thrust of the slender missile model. The problem that a traditional engine ground static ignition test