This study is a multicenter, non-randomized, open-label, Phase Ib/II combination therapy trial. The trial consists of two parts: Part 1 (Phase Ib), dose-escalation of combination therapy, followed by Part 2 (Phase II), tumor-type exploration of combination therapy. This study will evaluate the RP2D, safety, tolerability, and preliminary efficacy of BM230 in combination with PD-1 inhibitor in patients with HER2-related solid tumors (including but not limited to colorectal cancer, esophageal squamous cell carcinoma, urothelial carcinoma, cholangiocarcinoma, endometrial cancer, cervical cancer, ovarian cancer, etc.).