Objective To explore the clinical value of endoscopic ultrasonography(EUS)combined with serum serine protease inhibitor Kazal 1(SPINK1)and secretory phosphoprotein 1(SPP1)in early diagnosis of esophageal cancer.Methods 276 patients from June 2021 to May 2023 were selected as the study objects.92 cases of esophageal cancer diagnosed by operation and pathology were esophageal cancer group,another 89 patients diagnosed as benign esophageal lesions through tissue biopsy were selected as the benign lesion group,and 95 healthy individuals who underwent physical examinations were collected as the healthy control group,general information such as age and gender of subjects in three groups were collected and organized;using pathological results as the gold standard,the accuracy of EUS in diagnosing esophageal cancer was verified;the expression of serum SPINK1 and SPP1 was compared among the esophageal cancer group,benign lesion group,and healthy control group;the relationship between the expression of serum SPINK1 and SPP1 in esophageal cancer patients and their clinical and pathological characteristics was explored;efficacy of EUS combined with serum SPINK1,SPP1 levels for early diagnosis of esophageal cancer was analyzed using receiver operator characteristic curve(ROC curve).Results Compared with the gold standard,the results of EUS examination showed that 81 cases were diagnosed with esophageal cancer,79 cases were diagnosed with benign lesions,11 cases were missed diagnosed,and 10 cases were misdiagnosed,with an accuracy rate of 88.40%(160/181);Compared with the healthy control group and the benign lesion group,the expression levels of serum SPINK1 and SPP1 in the esophageal cancer group were obviously increased,the expression levels of serum SPINK1 and SPP1 in the benign lesion group were significantly higher than those in the healthy control group,the differences were statistically significant(P<0.05);Serum SPINK1 expression was linked to tumor diameter>2 cm,presence of lymph node metastasis,lymph node positivity,and tissue grading level 3 in patients(P<0.05).Serum SPP1 expression level was related to tumor diameter>2 cm,presence of lymph node metastasis,lymph node positivity,and estrogen receptor positivity of patients(P<0.05);ROC curve showed that the area under the curve(AUC)of EUS,serum SPINK1,SPP1 levels,and their combination in the early diagnosis of esophageal cancer was 0.862,0.834,0.782,and 0.926,respectively,the clinical efficacy of the combination of the three in the early diagnosis of esophageal cancer was superior to that of EUS,serum SPINK1,and SPP1 alone(Z=2.30,Z=3.70,Z=4.23,P=0.022,P=0.000,P=0.000).Conclusion The expression levels of serum SPINK1 and SPP1 in esophageal cancer patients are abnormally up-regulated.The combination of EUS and serum SPINK1 and SPP1 has high clinical value in early diagnosis of esophageal cancer.