Objective To analyze the pathways, biomarkers and diagnostic genes of systemic sclerosis associated interstitial lung disease (SSc-ILD) using bioinformatics. Methods SSc-ILD related gene data sets from April to June 2023 were downloaded from the Gene Expression Omnibus database for differential analysis and enrichment analyses including gene ontology analysis, Kyoto Encyclopedia of Genes and Genomes analysis, disease ontology analysis, and gene set enrichment analysis. Least absolute shrinkage and selection operator regression and support vector machine algorithms were applied to screen and take the intersection to get the diagnostic genes and validate the results. Disease-related data were analyzed by immune cell infiltration. Results A total of 178 differential genes were obtained, and enrichment analyses showed that they were related to 5 signaling pathways and associated with 3 diseases. The diagnostic genes screened were TNFAIP3, ID3, and NT5DC2, and immune cell infiltration showed that the diagnostic genes were associated with plasma cells, resting mast cells, activated natural killer cells, macrophage M1 and M2, resting dendritic cells, and activated dendritic cells. Conclusion The screened diagnostic genes and immune cells may be involved in the development of SSc-ILD.