将损伤理论引入混凝土的断裂分析中,采用Loland模型推导出混凝土I-Ⅱ复合型裂缝缝端损伤区临界区域的公式,并基于复合裂缝断裂判据推导出I-Ⅱ复合型裂缝的缝端微裂纹区临界区域的公式,并引用相关文献中的混凝土参数作为实例,求出其最小断裂半径以及对应的最小损伤半径.通过实例说明了混凝土损伤断裂的过程. The damage theory is introduced into the fracture analysis of concrete, and the formula of the critical region of I-Ⅱ composite crack tip is deduced by Loland model. The crack tip of I-Ⅱ composite fracture is deduced based on the composite fracture criterion The formula of the critical region of the crack zone and the concrete parameters in the relevant literature are cited as an example to find the minimum radius of the fracture and the minimum radius of the corresponding damage.The process of concrete damage and fracture is illustrated by an example.