Vibratory rock fragmentation has the characteristics of low energy consumption and low required axial pressure. In order to improve the efficiency of rock fragmentation while controlling costs， a study was conducted on the rock fragmentation mode combining vibration and pressure. This article takes red sandstone as the research object and conducts research on the crack propagation law inside the rock when spherical teeth invade red sandstone under dynamic and static composite loading. The results indicate that the degree of rock fragmentation under the spherical tooth increases with the increase of dynamic and static loads， and only when the combined load peak reaches 100kN， will the rock undergo significant volumetric fragmentation. In the early stage of rock breaking， when the load is small， the rock tends to develop lateral cracks， and the rock damage becomes “wide and shallow”. As the load increases， the rock tends to develop deep cracks in the middle， followed by lateral cracks， which exhibit a "narrow and deep" characteristic. The various indicators of rock fragmentation are affected by different load parameters to varying degrees： that is， under the same amplitude increment conditions， the degree of fragmentation caused by increasing the dynamic load amplitude is greater than that caused by increasing the same static load. The above conclusions can provide important support for improving the efficiency of dynamic and static load composite crushing of hard rock and overcoming the technical difficulties of hard rock drilling.