This paper proposed four different sub-constructions of the ‘X+Si’ construction group based on the meaning of ‘Si’ and analyzed the status and the typicity of each sub-construction depending on whether there is calculability. According to my research, it is found that ‘X₁+Si₁’ is a typical group member and grammatical construction. As for ‘X₂+Si₂’ and ‘X₃+Si₃’, both of them are untypical group member, but they can also be considered as grammatical construction due to their high grammaticalization degree. Meanwhile, ‘X₄+Si₄’ is an untypical group member and rhetoric construction. This paper attempted to draw the conclusion that the meaning extension is caused by the multi-interaction of various cognitive domains, such as construction & lexical morpheme, construction & syntactic element, syntax & semantics, rhythm & syntax, pragmatics & syntax. The mechanisms causing the result can be explained by analogy, reanalysis, metonymy, metaphor, pragmatic inference, and context absorption.