Impact loading tests were carried out on four types of 2-2 cement-based piezoelectric composites with the same volume fraction and different functional phase sizes by using the Split Hopkinson Bar device, and the electromechanical response characteristics of 2-2 cement-based piezoelectric composites with different functional phase sizes under impact load were studied. The maximum dynamic compressive strength of the four composites increases with the increase of the size of the functional phase, and under the same strain, when the size of the functional phase is 1mm, the composite sample has the maximum compressive strength; The change trend of potential shift time history curves of the four composites is essentially the same, which increases with the increase of strain rate, and the increase amplitude decreases with the increase of strain rate; There is a critical point in the electromechanical response relationship of the four composites. When the size of the functional phase is 1mm, the composites have the maximum dynamic sensitivity.