Circular RNA (circRNA) is a closed-loop, single-stranded RNA molecule that plays a variety of important roles in cells, such as regulating transcription, regulating miRNA activity with ceRNA. In the pCE-RB-Mam circular RNA overexpression vectors, the two wings of multiple cloning sites efficiently facilitate the inverted repeat sequence of RNA excision, transcribe the sequence inserted into multiple cloning sites for circular excision, thereby implementing circRNA overexpression.