This is a Phase II, prospective, single-arm exploratory clinical trial designed to evaluate the efficacy and safety of stereotactic body radiotherapy followed by ipilimumab N01 plus sintilimab in combination with nab-paclitaxel and gemcitabine in patients with locally advanced pancreatic cancer. Eligible patients will receive SBRT followed by sequential systemic therapy. The primary endpoint is progression-free survival, and secondary endpoints include overall survival, disease control rate, duration of response, objective response rate, and safety.