This study is a multicenter, randomized, open-label, parallel-control Phase III clinical trial enrolling patients with unresectable HER2-negative, EGFR-positive recurrent/metastatic breast cancer who have previously failed first- or second-line chemotherapy. It aims to compare the efficacy and safety of SYS6010 monotherapy versus investigator-selected chemotherapy.The study plans to enroll approximately 400 subjects, randomly assigned in a 1:1 ratio to the treatment arm and control arm(Investigator's choice of standard chemotherapy regimen, including eribulin, capecitabine, gemcitabine, or vinorelbine).