During the development of the civil aircraft, the design requires that the vibration level of the airborne equipment should be higher than the value specified in the standard. In fact, because the supplier’s equipment is a shelf product, the vibration environment test may not be carried out according to the DO-160G specification. In order to meet the requirements of the equipment vibration environment test, it is necessary to adopt corresponding damping measures to reduce the response of the equipment before the support is installed and used. In this paper, a certain type of bracket was used as the research object. the modal and random response analysis of the typical bracket were carried out, and a sinusoidal frequency sweep test is performed on the dummy and the mounting bracket. According to the frequency sweep test data in various directions, the dynamic model of each order response of the finite element model was modified, and stiffness and damping elements were added. The corrected modal frequency error was within 2%, and the peak error at the corresponding modal frequencywas within 5%. Then, a vibration isolation design was carried out for the dummy-bracket system. By adding a vibration isolator and pasting a damping layer at the connection between the bracket and the fuselage, the simulated random response after vibration isolation was 20 dB lower than the DO-160G standard spectrum. The results show that the vibration isolation measures are effective.