The impact p rocess of hydraulic drifter is a periodic vibrat ion course with position feedback and p iston control by shuttle valve. For the phenomena of secondary or mult iple v ibrations within one period during cyclic impact process of hydraulic drifter, this study establishes a dynamic mod el of the system during hydraulic impact and analyzes the vibration behavior of piston in the impact process of hydraulic drifter fro m the perspectives of velocity recovery coefficient R, acceleration ratio K F , and accelerat ion switching t ime K t . Then, the impact point position for the nonlinear periodic motion of the piston is observed through point transformation and Jacobian technique. Subsequently, a spatial scope defined by correlated system parameters R, K F , and K t is identified, within this scope, the p iston only stably vibrates once within one impact period. Finally, the position of the signal port is redesigned on the basis of the existence scope, and the design parameters for the hydraulic drifter are improved. The correctness of the derivation p rocess and the conclusion of this study are experimentally verified. The present findings provide a basis for reasonably match ing the relationships among design parameters and can help improve drifter impact efficiency.