通过对覆膜盐和覆膜砂试样断口的扫描电镜分析，得出覆膜盐试样破坏是以盐粒与粘结剂之间的界面破坏，即以附着断裂为主，而覆膜砂试样的破坏是以粘结剂的内聚断裂为主的结论。选取适宜的表面活性剂处理树脂或盐粒，可以改善树脂与盐粒的润湿能力，使其由附着断裂为主转变为以内聚断裂为主。 Through the scanning electron microscopy analysis of the coated salt and coated sand samples, it is concluded that the damage of the coated salt sample is caused by the interface damage between the salt particles and the binder, that is, The failure of the sample is based on the conclusion that the binder cohesive fracture. The selection of the appropriate surfactants to treat the resin or salt particles can improve the wetting ability of the resin and the salt particles, and mainly change from the adhesion-breaking to the cohesive-fracture.