"学位证书持有者" can be translated into English as "degree certificate holder".
This phrase clearly conveys the meaning of someone who possesses a degree certificate. If you need to be more specific about the type of degree, you could add an adjective, such as "bachelor's degree certificate holder" (学士学位证书持有者), "master's degree certificate holder" (硕士学位证书持有者), or "doctoral degree certificate holder" (博士学位证书持有者).