Abstract: Plasma particle simulation wave spectral response to electrostatic wave is systematically analyzed. We introduce the wave spectral-response function of plasma particle simulation.The response expre-sion in following case is derived respectively, Finite-Size-Particle with Gauss, triangle and square shape, its dipole expansion near grid point, finite difference and FFT solving process of Poisson equation. The influence of shape, size and treatment of Finite-Size-Particle, space discreteness and solving process of Poisson equation on particle simulation spectral response and the depression of short wave noise are discussed.