Abstract: Objective To explore the effects of WeChat-based symptom assessment and self-intervention on adverse reactions, mental status and quality of life in patients with breast cancer during chemotherapy. Methods One hundred and forty-six patients with breast cancer who were treated with chemotherapy in our hospital from September 2017 to September 2018 were selected and divided into experimental group and control group according to the random number table method, with 73 cases in each group. Patients in the control group were given outpatient guidance during chemotherapy, and patients in the experimental group were given a WeChat remote evaluation and intervention platform during chemotherapy. Beck anxiety scale(Beck anxiety inventory, BAI), Beck depression scale(Beck depression inventory, BDI), psychological elasticity scale(Connor-Davidson resilience scale, CD-RISC), Heah hope scale(Herth Hope Index, HHI), Happiness index scale(Index of well-being, IOWB), Morisky medication Compliance scale, Quality of life measurement scale and incidence of serious adverse events were compared between the two groups. Results The BAI and BDI scores of the two groups were lower than those before the intervention, and the experimental group was significantly lower than the control group(all P<0.05). The psychological resilience scale, HHI, IOWB, and quality of life scores of the two groups were higher than those before the intervention, and the experimental group was significantly higher than the control group(all P<0.05). The adherence of the patients in the experimental group was significantly higher than that in the control group in the early, middle and late stages, and both showed a downward trend(all P<0.05). The incidence of serious adverse reactions in the experimental group was significantly lower than that in the control group(all P<0.05). Conclusion WeChat remote assessment and intervention platform can improve the psychological state of breast cancer patients during chemotherapy, improve treatment expectation and diagnosis and treatment, reduce the incidence of serious adverse reactions, and significantly improve the quality of life.