Protein translation using circular rna and application thereof

A circular RNA construct which has a structure as shown in Formula I from the 5′-3′ direction:

• TI-Z1-Z2 (I)
• wherein
• TI is a translation initiation element;
• Z1 is an expression cassette for expressing a foreign protein;
• Z2 is none or an other component;
• and, each “-” is a bond or a nucleotide connection sequence;
• wherein, the length of the TI element is 6-30 nt, preferably, 8-24 nt, more preferably, 10-20 nt;
• in the TI element, the content of A is ≥35%, preferably, ≥45%, more preferably, ≥60%;
• in the TI element, the content of T is ≥20%, preferably, ≥30%, more preferably, ≥50%;
• in the TI element, the content of A+T is ≥65%, preferably, ≥80%, more preferably, ≥90%;
• in the TI element, the content of G is ≤35%, preferably, ≤25%, and more preferably, ≤10%.