The invention relates to a catalyst for producing cyclohexylbenzene, a preparation method of the catalyst and a method for synthesizing cyclohexylbenzene by a benzene hydroalkylation one-step method,and mainly solves the technical problems that in the prior art, the yield of the by-product cyclohexane is high and the yield of cyclohexylbenzene is low in the reaction of the catalyst in the prior art. According to the invention, the catalyst used for cyclohexylbenzene production is adopted, wherein the catalyst comprises a carrier and the following active components: (1) 0.5g-20 g/L of Pd; (2)0-50 g/L of at least one element selected from lanthanide elements; (3) 0-30 g/L of at least one element selected from group IB elements; the carrier is a hydrogen type zeolite molecular sieve. According to the technical scheme, the good effect is achieved, and the catalyst can be used for preparing cyclohexylbenzene by a benzene hydroalkylation one-step method.