Provided are a β-coronavirus multimeric antigen, a preparation method therefor and an application thereof, the amino acid sequence of the β-coronavirus multimeric antigen comprising: some amino acid sequences or all amino acid sequences of receptor-binding domains (RBDs) of a plurality of spike proteins of a β-coronavirus, the spike proteins directly forming a series connection or being in series by connecting to amino acid sequences, the some amino acid sequences or all amino acid sequences of the RBDs of the serially connected spike proteins being derived from the same β-coronavirus, and the plurality being an integer≥3. A SARS‑CoV‑2 RBD multimer may be stably expressed, and an immune response may be strongly induced after immunizing mice; in addition, a neutralizing antibody titer produced by the induced mice is significantly different from that of a SARS‑CoV‑2 RBD dimer.
β-CORONAVIRUS MULTIMERIC ANTIGEN, PREPARATION METHOD THEREFOR AND APPLICATION THEREOF