Multicultural writing in immigrant literature presents a new narrative style of world literature in the era of globalization, showing the qualities of different cultural games and mingling, and is also an important manifestation of the evolution of the traditional European colonial relationship in the process of globalization. Taking the works of Kazuo Ishiguro and Zadie Smith as an example, the study crawls the readers’ comment data of related works on relevant websites based on the text mining method, and utilizes the methods of TF-IDF algorithm, LDA theme model, and sentiment analysis to carry out the mismatch analysis of immigrant culture, and to shape the image of memory and identity of immigrant culture. The results of the study show that the works of Kazuo Ishiguro and Zadie Smith can be categorized into five themes, namely, identity and belonging, cultural conflict and integration, immigrant experience and intergenerational, social and political contexts, and emotional and psychological states, and that the readers’ perception of immigrant culture of Kazuo Ishiguro’s and Zadie Smith’s works is dominated by positive emotions, with a positive tendency of 92.04%. Based on the results of IPA quadrant distribution, it can be obtained that the number of elements falling into the second four quadrants is the highest, i.e., the works of the two authors are able to express the content of immigrant’s memory and identity well, and the readers are able to explore a lot of literary knowledge about immigrant’s memory and identity construction in Kazuo Ishiguro’s and Zadie Smith’s works.