In order to address the issues of high grouting pressure and poor slurry diffusion uniformity caused by the lack of cracks in the casing material during sleeve valve pipe grouting, a method of pre-splitting the casing material using pulsed gas is proposed. The acoustic emission characteristics and crack evolution mechanism of the casing material under the action of pulsed gas were studied. Based on a self-constructed pulsed gas loading device combined with acoustic emission nondestructive testing technology, experimental research on the pulsed gas splitting of the casing material was conducted. The acoustic emission characteristics during the damage process of the casing material were analyzed through acoustic emission parameter analysis, and the effect of pulsed gas splitting was evaluated. The development and identification of crack types in the casing material were carried out using the comprehensive RA-AF analysis method and the Gaussian mixture model (GMM). The research results show that the entire acoustic emission evolution process can be divided into the crack generation and propagation (Ⅰ) stage and the post-peak damage (Ⅱ) stage. In terms of acoustic emission characteristics, the splitting effect of the pulsed gas on the casing material aged for 3 and 5 d is better than that at 7 d. Considering the compressive strength requirements, the splitting effect of the A2 group casing material is optimal when aged for 5 d. As the loading progresses, the RA-AF data points move towards high RA values and low AF values, with the proportion of tensile cracks decreasing and the proportion of shear cracks increasing. The failure mode is a mixed tensile-shear failure dominated by shear failure.