The CRISPR-Cas13d protein targets RNA substrates through crRNA-mediated sequence-specific binding and achieves precise cleavage via its ribonuclease activity， offering a non-genome-editing strategy for RNA-level gene regulation. In this study， we optimized the Cas13d gene sequence based on the codon preference of medaka （Oryzias latipes）， successfully constructed a prokaryotic expression system， and purified recombinant Cas13d protein with a molecular weight of 115 ku. By microinjecting in vitro-transcribed Cas13d mRNA complexed with crRNA targeting the tyrosinase gene （tyr） into medaka embryos， alongside parallel experiments using Cas13d protein/crRNA ribonucleoprotein （RNP） complexes， we systematically evaluated RNA-editing efficiency. qRT-PCR and sequencing analyses demonstrated that both delivery methods significantly reduced tyr RNA levels in embryos （P<0.01）， while DNA sequencing confirmed the absence of mutations in the target DNA sequences. This study validates the effectiveness and specificity of Cas13d-mediated gene silencing through RNA editing in medaka， not only providing a novel regulatory tool for fish genetic research but also establishing a theoretical foundation for developing RNA-targeted Cas13d antiviral transgenic fish lines.