Diplomatic attitudinal expressions refer to new vocabulary and new concepts expressed by the government in diplomatic contexts, which belong to typical languages of evaluation. Diplomatic attitudinal expressions are an important part of the diplomatic discourse and even the core composition of the diplomatic discourse system. Their special attributes determine that they should be examined from a multidisciplinary perspective such as linguistics, diplomacy and communication. In the interdisciplinary perspective of the ″Appraisal System″ of Systemic Functional Linguistics and the ″political equivalence″ principle of diplomatic translation, the relationship between diplomatic attitudinal expressions and the diplomatic context is supervenient instead of circumvenient. It is not the diplomatic context that determines what diplomatic language is used. On the contrary, it is the diplomatic language used that embodies the diplomatic context and diplomatic attitude.  In the process of translating diplomatic expressions, same type of evaluation is the first principle, namely, commendatory terms to commendatory terms, derogatory terms to derogatory terms, and correspondence of evaluation key. The evaluation key refers to the fixed tendency of a certain evaluation and the evaluation feature of maintaining a unified diplomatic position. The correspondence consists of two dimensions: diachronic and synchronic. Diachronic correspondence means that the diplomatic expressions should be stable and consistent in a certain period of time, forming a set of evaluation tone with fixed diplomatic vocabulary. Synchronic correspondence means that in a fixed evaluation domain formed by the government on a fixed diplomatic object, diplomatic expressions should form an evaluation unity, with steady and same appraisal words together as a whole. For a fixed country or a fixed diplomatic issue, the government should use a fixed expression to express the attitude of evaluation. At present, the English translation of the important diplomatic expression ″can bai″(参拜) in China does not conform to the principle of equivalence of evaluation types, and also does not conform to the principle of equivalence of specific diplomatic attitudes, failing to maintain the unity of diplomatic positions in both the synchronic and diachronic dimensions. Firstly, the Ministry of Foreign Affairs of China translates ″can bai″ as ″visit″, which is a semantic evaluation of neutrality. This translation resulted in the lack of diplomatic attitudes of the Chinese government in the English version. Secondly, the Chinese government's use of the word ″can bai″ in the diplomatic context has formed an evaluation tone in the synchronic and diachronic dimensions. It has been given special evaluation semantics and is only used to evaluate Japanese officials' visiting to the Yasukuni Shrine. But the use of the English word ″visit″ also includes neutral evaluation semantics, and even high-level commendatory evaluations. Therefore, compared with the original Chinese word ″can bai″, the English translation ″visit″ lacks the evaluation tone, and cannot convey the unity of the diplomatic position of the original text. The translation of diplomatic expressions is an important part of the construction of China's diplomatic discourse system. Under the goal of building a shared future for mankind in the new era, the translation and overseas publicity of diplomatic attitudinal expressions need to introduce a broader perspective of multidiscipline and a deeper theoretical observation.