Against the backdrop of regional economic integration in East Asia and the rapid development of cross-border e-commerce, the scale of online cross-border consumption in China, Japan, and the Republic of Korea continues to rise, with issues such as jurisdictional conflicts in cross-border consumer rights protection, excessively high costs, and difficulties in evidence collection becoming increasingly prominent. This paper employs a comparative analysis approach to systematically examine the legal systems and core institutions for cross-border consumer rights protection in the three countries, compare their similarities and differences as well as advantages and disadvantages, and delve into the underlying causes of difficulties in rights protection. From two dimensions—domestic legislative optimization and regional collaboration—the paper proposes targeted and feasible solutions. The study reveals that while the legislative philosophies of the three countries are convergent, significant differences exist in institutional details. Only by addressing legislative shortcomings and establishing a transnational rights protection collaboration mechanism can the challenges in cross-border rights protection be overcome, consumer rights and interests be safeguarded, and the healthy development of cross-border trade among the three countries be promoted.