Based on the theory of chirped pulse broadband amplification dynamics, this paper systematically analyzes the amplification characteristics and pulse width compression characteristics of chirped pulses in Nd:glass multi-pass amplification systems using numerical simulation. The effects of different input parameter configurations of the amplification system on the characteristics of the amplified pulse parameters, the pulse width and the compressed pulse signal-to-noise ratio were analyzed without spectral pre-compensation. By using the forward iterative algorithm based on the modified input pulse, the required input pulse waveform and spectral distribution were obtained for a given output pulse. The inversion calculation of chirped pulses with three-dimensional spatial distribution is performed, and the amplification characteristics of small signal gain coefficient with spatial inhomogeneous distribution are analyzed. A solution to the large amount of data in broadband amplification calculation is given. The results of this paper can be used as a reference for the optimal design of chirped pulse amplification in high power Nd:glass multi-pass amplification system.