The invention discloses a single-nucleotide polymorphism (SNP) detection specific primer of the CYP2C19 gene and a liquid phase chip. The liquid phase chip contains an ASPE primer composed of a tag sequence on the 5'-end and specific primers on the 3'-end which aims at the target genetic mutation, microspheres covered by the anti-tag sequence and an amplification primer, wherein the specific primers contain SEQ ID NO.25 and SEQ ID NO.26, SEQ ID NO.27 and SEQ ID NO.28 aiming at the C194T SNP site, SEQ ID NO.29 and SEQ ID NO.30, SEQ ID NO.31 and SEQ ID NO.32, SEQ ID NO.33 and SEQ ID NO.34, SEQID NO.35 and SEQ ID NO.36, SEQ ID NO.37 and SEQ ID NO.38, SEQ ID NO.39 and SEQ ID NO.40, SEQ ID NO.41 and SEQ ID NO.42, SEQ ID NO.43 and SEQ IDNO.44, SEQ ID NO.45 and SEQ ID NO.46, and / or SEQ ID NO.47 and SEQ ID NO.48. The coincidence rate of the detection result of the SNP detection liquid phase chip of the CYP2C 19 gene and the detection result adopting a sequencing method is up to 100%.