Abstract: This study investigates the low velocity impact and vibration characteristics of pleated sandwich composite panels with shear hardening gel by adopting a combination of theory and experiment. Based on the mean value equivalence theory and Reddy high-order shear deformation theory, combined with the modified Tsai Hill and the Christensen failure criterion, an integrated dynamic model of impact and vibration is established. This model enables the prediction of parameters, including frequencies, force-displacement curves, and post-impact vibration responses. The research results indicate that at 10 J impact energy, the damage diameter of the filled specimen is 11.1 mm, which is 31.9% lower than the 16.3 mm observed in the unfilled specimen. Furthermore, the frequencies of the filled specimen did not experience a significant decrease after impact. A comparison of the first three peak-to-peak values of the time-domain vibration response curves reveals an average reduction rate of 9.2% in the vibration response for the filled specimen, demonstrating that filling with shear-hardening gel can enhance both the impact resistance and vibration damping performance of the structure. The model developed in this study exhibits high calculation accuracy, and the prediction errors of the above vibration and impact parameters are within the ideal range. It can provide effective support for the impact protection and vibration damping design of such structures, demonstrating broad application prospects in fields such as aerospace.