Roof-cutting blasting by explosives involves certain operational risks and is prone to cause damage to surrounding rock. Accordingly, a new non-explosive directional rock-breaking technology called Instantaneous Expansion with a Single Fracture (IESF) has been developed. This paper focuses on the research of the crack propagation behavior and damage extent of rock mass under the action of IESF. Firstly, the directional rock-breaking principle of IESF is analyzed, and the theoretical radius of the crushed zone ( R c ) and fracture zone ( R f ) for conventional blasting (CB), shaped-charge blasting (SCB), and IESF under cylindrical charge conditions are derived. Subsequently, a field comparative experiment of the three methods was conducted. The results showed that CB produced cracks in random orientations around the hole wall, SCB produced secondary cracks in addition to two primary cracks in splitting direction, and the cracks produced by CB and SCB contain both Mode I and Mode II. Conversely, IESF only produces Mode I cracks in the presplitting direction. Finally, R c and R f of the three numerical models considering the rock mass heterogeneity were statistically analyzed, the results demonstrate that R c (IESF) < R c (SCB) < R c (CB), while R f (IESF) > R f (SCB) > R f (CB). The statistical analysis of the monitoring point pressure and Young's modulus during the damage process further verified the directional rock-breaking mechanism of IESF. The research results have improved the theoretical system of IESF and contributed to the promotion and application of IESF technology. Highlights: Through field tests, the crack propagation behavior of the rock mass in the borehole under conventional blasting (CB), shaped-charge blasting (SCB), and instantaneous expansion with a single fracture (IESF) was investigated. Theoretical radius of the crushed zone ( R c ) and fracture zone ( R f ) of rock mass under the action of CB, SCB, and IESF under cylindrical charge conditions were derived. Three numerical models considering the heterogeneity of rock mass were established based on the theory of progressive damage failure, and numerical solutions for R c and R f under three rock-breaking technologies were obtained, verifying the accuracy of the analytical solutions. The superiority of IESF in directional rock-breaking was verified through comparative analysis of the damage range of rock mass under three rock-breaking technologies [ABSTRACT FROM AUTHOR]