First, the differential equations of the motion of a Stewart shock isolation platform are established. The three-directional dynamic stiffness characteristics of the platform are analyzed. The effect of stiffness on the shock isolation performance of the platform is discussed. Then, a drop-type shock test is performed on the platform. The results are compared with that of the simulation, proving that the dynamic stiffness of the passive Stewart shock isolation platform is approximately linear. The horizontal shock isolation rate of the Stewart platform is greater than the longitudinal shock isolation rate, which is greater than the vertical shock isolation rate. Moreover, the shock isolation rates of the test in all three dimensions are greater than 86.39%. These results provide the theoretical and experimental foundation for the practical application of the Stewart platform forshock resistance inship equipment.