For a impulsive Lasota-Wazewska model with a piecewise continuous coefficient, it studies the change of the properties of the model’s solution when the coefficients of the model are piecewise continuous almost period. Using fixed point theorem, it is proved that the existence of the piecewise almost periodic solutions. Studies have shown that the continuity of the solution of the model is mainly affected by the impulsive term and the piecewise almost period is affected by both the piecewise almost periodicity of the coefficients and the almost periodicity of the impulsive term.