Resonance penetration is an important phenomenon in one-dimensional quantum scattering. In general textbooks, the explanation of this phenomenon assumes monochromatic plane wave incidence, and there is a lack of research on wave packet incidence which is closer to the actual situation. In this paper, the main characteristics of wave packet scattering in one-dimensional square well and the influence of the mean and broadening of incident wave packet’s energy on resonance penetration are discussed in detail by means of analytical derivation and drawing. The research content of this paper can not only deepen the understanding of resonance penetration phenomenon, but also provides a general method for the analysis of the scattering problem of arbitrary piecewise constant potential function.