Objective: To explore the distribution of traditional Chinese medicine (TCM) syndromes in patients with interstitial lung disease (ILD) and its influencing factors. Methods: This cross-sectional study included 385 patients with ILD admitted to the First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine) from January 2018 to June 2022. Data on sex, age, body mass index, smoking history, respiratory rate, hospitalization time, treatment cost, whether velcro rales can be heard, comorbidities with rheumatic immune diseases, TCM four examination information, and clinical examination results, including CT imaging, D-dimer level, and lung function-related indicators, were collected. The distribution pattern of TCM syndromes in patients with ILD and the association between TCM syndromes and clinical indicators were analyzed using the cluster analysis and binary Logistic regression analysis. Results: Among the 385 patients with ILD, sticky phlegm (59.74%) and shortness of breath (56.10%) were common symptoms, while greasy tongue coating (55.32%), red tongue (52.73%), and slippery and rapid pulse (25.71%) were common tongue and pulse manifestations. The patients were divided into five syndromes using cluster analysis: syndrome of phlegm-heat stagnation in the lung (36.62%), syndrome of turbid phlegm obstructing lung (29.35%), syndrome of deficiency of both qi and yin (12.99%), syndrome of qi deficiency of lung and kidney (11.95%), and syndrome of phlegm and blood stasis obstructing lung (9.09%). The D-dimer level was lower in patients with syndrome of phlegm-heat stagnation in the lung, syndrome of turbid phlegm obstructing lung, syndrome of deficiency of both qi and yin, and syndrome of qi deficiency of lung and kidney than in those with syndrome of phlegm and blood stasis obstructing lung (P<0.05). The percentage of predicted forced vital capacity (FVC%pred) of patients with syndrome of phlegm-heat stagnation in the lung, syndrome of turbid phlegm obstructing lung, syndrome of deficiency of both qi and yin, and syndrome of phlegm and blood stasis obstructing lung was higher than in those with syndrome of qi deficiency of lung and kidney (P<0.05). Among patients aged 60 and above, those with syndrome of phlegm-heat stagnation in the lung, syndrome of phlegm and blood stasis obstructing lung, and syndrome of deficiency of both qi and yin containing dual pathogenic syndrome elements were more likely to experience moderate to severe pulmonary diffusion impairment than those with syndrome of turbid phlegm obstructing lung and syndrome of qi deficiency of lung and kidney containing single pathogenic syndrome elements (P<0.05). The Logistic regression showed that the FVC%pred was an influential factor for syndrome of qi deficiency of lung and kidney, and the area under the receiver operating characteristic (ROC) curve (AUC) between FVC%pred and the formation of syndrome of qi deficiency of lung and kidney was 0.676 (95%CI: 0.598-0.755), P=0.002. The sensitivity was 0.431, the specificity was 0.966, and the best threshold on the ROC curve of 0.397 was 79.1%. The D-dimer level was an influential factor in the formation of syndrome of phlegm and blood stasis obstructing lung. The AUC between D-dimer level and the formation of syndrome of phlegm and blood stasis obstructing lung was 0.729 (95%CI: 0.655-0.802), P<0.001. The sensitivity was 0.914, the specificity was 0.523, and the best threshold on the ROC curve of 0.437 was 0.675 mg/L. Conclusion syndrome of phlegm-heat stagnation in the lung and syndrome of turbid phlegm obstructing lung are common among patients with ILD. Complex pathological syndromes are more likely to exacerbate pulmonary diffusion dysfunction. The FVC%pred can assist in differentiating syndrome of qi deficiency of lung and kidney, whereas the D-dimer level can assist in differentiating syndrome of phlegm and blood stasis obstructing lung.