This study addresses a critical gap in English language education at local application-oriented universities: how to enhance English majors’ international communication competence (ICC) through a systematically designed public speaking and debate course. A pre-course survey revealed three major problems: low conceptual awareness of ICC, a severe skills imbalance between daily conversation and public persuasion, and a “China narrative void” where students could introduce traditional culture but not contemporary China. To address these gaps, a “Three-Phase, Four-Loop” instructional model grounded in the Production-Oriented Approach and Zone of Proximal Development theory was implemented in a 16-week course for second-year English majors. The model integrates an eight-module “China Topics” vocabulary bank, scaffolded skill training, and low-risk, high-fidelity simulation activities. A post-course survey showed significant improvements: ICC conceptual understanding rose from near zero to 87.21% high familiarity; confidence in formal debate reached 72.1%; constructive communication behaviors increased from under 20% to over 58%; and students became able to confidently introduce contemporary topics such as high-speed rail and rural revitalization. Overall course satisfaction was 89.54%, with core reform measures rated as helpful by over 90% of students. The study provides a replicable, evidence-based pathway for cultivating international communication competence in similar applied undergraduate institutions.