Objective:To explore the mediating effect of self-advocacy between posttraumatic growth and social isolation among female breast cancer survivors, so as to provide reference for the establishing nursing intervention strategies for social isolation.Methods:A random samplingsurvey was conducted, a total of 220 female breast cancer survivors from May to December 2021in Tianjin Cancer Hospital Airport Hospital were recruited by convenience sampling method. They were investigated by the general information questionnaire, General Alienation Scale, Posttraumatic Growth Inventory and Female Self-advocacy in Cancer Survivorship, respectively.Results:A total of 203 valid questionnaires were collected. The score of posttraumatic growth was (60.91 ± 12.04) points, self-advocacy was (59.56 ± 12.19) points, social isolation was (36.52 ± 7.79) points of female breast cancer survivors. The Posttraumatic Growth Inventory scores of each dimension in female breast cancer survivors were positively correlated with the scores of female self-advocacy of each dimension in cancer survivorship ( r values were 0.219-0.686, all P<0.01); each dimension of the General Alienation Scale scores were negatively correlated with the scores of Posttraumatic Growth Inventory and Female Self-advocacy in Breast Cancer Survivorship ( r values were -0.804 to -0.202, all P<0.01). The posttraumatic growth of female breast cancer survivors affected social alienation through self-advocacy, which showed the mediating effect of self-advocacy accounts for 32.8% of total effect. Conclusions:Self-advocacy plays a mediating role in the relationship between posttraumatic growth and social isolation. Nurses can improve the level of self-advocacy of female breast cancer survivors and promote posttraumatic growth, so as to decrease social isolation.