This paper explores the effects of honorific grammar knowledge and pragmatic knowledge on learners' acquisition of Japanese honorifics through honorific grammar level and pragmatic level tests. The results of multiple linear regression analysis show that: (1) the acquisition of honorific grammar and pragmatic knowledge is insufficient due to the influence of the learning stage and the current situation of Japanese language teaching; (2) the knowledge of honorific grammar and pragmatic knowledge both positively affect the acquisition of honorifics, and the knowledge of pragmatic knowledge has a greater impact on the acquisition of honorifics; (3) the knowledge of Respectful language has a greater impact on the degree of honorifics acquisition than the knowledge of honorifics of Humble language. The teaching process of honorific language can try the dynamic teaching of grammatical knowledge and pragmatic knowledge, and learners should also strengthen the practice and pay special attention to the acquisition of pragmatic knowledge.