Language is the carrier of culture, bearing the national cultural information. As the most culturally-loaded element in any language’s vocabulary, idioms have aroused more and more attention. This paper starts with the analysis of the relationship between culture, idioms and translation, and makes an investigation of cultural factors affecting idiom translation such as subjective and objective factors. Based on these analyses, the paper will propose the cultural translation principles and strategies focusing on cultural connotations of idioms in order to transfer the English idioms translation from the language level to the cultural level.