A catalyst composition for preparing o-phenylphenol is provided. The catalyst composition includes a carrier; and a first active metal, a second active metal, and a catalytic promoter carried by the carrier. The first active metal is platinum, and the second active metal is selected from the first, second and third rows of transition metals of groups VIB and VIIIB. The present disclosure utilizes the carrier to carry the first active metal, the second active metal and the catalytic promoter so as to increase the selectivity of o-phenylphenol and the service life of a catalyst.