This study examined the effects of parents' posttraumatic stress symptoms (PTSS) and parenting behaviors, children's feelings of safety, and children's self-disclosure on children's PTSS, to elucidate the mechanisms underlying intergenerational effect of PTSS. Three months after the Super Typhoon Lekima occurred in China, August 2019, self-report questionnaires were used to investigate 866 Chinese parent-child dyads (children's mean age was 10.55 years, 52.2% were boys; parents' mean age was 37.99 years, 23.2% were fathers) in the area most affected by the typhoon. The results found that parents' PTSS may have disrupted the provision of emotionally warm parenting, in turn reducing children's feelings of safety and limiting their self-disclosure, ultimately increasing the severity of children's PTSS. This suggested that the mechanisms underlying the intergenerational effect of PTSS between parents and children involve the combined role of parents' emotionally warm parenting, children's feelings of safety, and children's self-disclosure.