Developing intelligent responsive platforms to carry out high-performance therapy is of great interest for the treatment of tumors and their metastases. However, effective drug loading, activity maintenance, off-target leakage, and response to collaborative therapy remain great challenges. Herein, a targeted intelligent responsive mesoporous polydopamine (MPDA) nanosystem was reported for use in gene-mediated photochemotherapy for synergistic tumor treatment. First, the MPDA was surface modified to maintain a positive charge near the surface and to impart active targeting. Then, gambogic acid (GA) was encapsulated in the MPDA, solidified by phase change materials (PCMs), and finally loaded with siRNA by electrostatic interactions to obtain the smart nanodelivery system (PPMD@GA/si). In vitro and in vivo experiments showed that it not only effectively avoids siRNA inactivation and accidental release of GA, but also possesses potential for targeted accumulation to tumor tissue and mild-temperature photothermal therapy and chemotherapy via near infrared (NIR) radiation. Additionally, the release of siRNA could also effectively inhibit tumor invasion and metastasis to realize multimodal synergistic therapy. Overall, our studies provide a promising idea for synergistic tumor and metastasis treatment based on vector construction.