Abstract: The fourth amendment to the Criminal Procedure Law of the People’s Republic of China (CPLPRC) has laid a new institutional foundation. Against this backdrop, the legal construction of the spousal/relative privilege against testifying (SRPAT) has emerged as a crucial issue in the modernization of criminal justice. This system is instrumental in demonstrating the refinement of criminal justice in the new era and in safeguarding human rights. It also contributes to responding to ethical norms and societal moral expectations, thereby enhancing the effectiveness of social governance. While SRPAT has been estabilshed in CPLRC, this legal innovation has not yet facilitated the revival of traditional legal culture. The concept of concealing wrongdoings among relatives rooted in traditional norms remains disconnected from modern criminal proceedings. This disconnect stems from the privilege’s ambiguous nature, narrow scope of applicable subjects, lack of procedural safeguards, and absence of sanctioning mechanisms. To establish a comprehensive system for SRPAT, the following logical paths should be followed. At the normative positioning level, it is essential to clarify the fundamental right attribute of the privilege. At the substantive normative level, the scope of subjects should be reasonably expanded to include siblings. Additionally, exceptions should be set for crimes against national security and domestic violence. At the procedural application level, a three-stage notification + clarification mechanism should be established throughout the entire process, from investigation to trial. At the level of rights remedy, the legal safeguards for the privilege need to be strengthened. This can be achieved through the double exclusion rule for relatives’ testimony. Furthermore, procedural sanctioning mechanisms should also be implemented to enhance the protection of the privilege.