Objective: After detecting the correlation between the expression of serum MMP-7 and MMP-9 and the degree of differentiation, depth of tumor invasion, and lymph node metastasis in patients with gastric cancer, gastric filling ultrasound, serum MMP-7, MMP-9 and combined screening in different stages of gastric cancer Middle value. Methods: A retrospective analysis of 82 patients with gastric cancer was admitted between February 2018 and February 2020, and they were all tested for serum MMP-7, MMP-9 and gastric filling ultrasound (FUS; Filling Ultra Ssound) to analyze the differentiation of serum in gastric cancer patients After the degree, the depth of tumor invasion, and the expression in lymph node metastasis, pathological biopsy, "International Anti-Cancer Alliance and American Cancer Federation TNM Staging System (8th Edition)" as the gold standard, use ROC to analyze gastric filling ultrasound and serum MMP -7. The value of MMP-9 and combined screening in different stages of gastric cancer. Results: The positive rate of MMP-7 and MMP-9 expression was correlated with the degree of differentiation, lymph node metastasis, and depth of invasion (P<0.05). The FUS has a total accuracy rate of 84.51% for T1 to T4, 85.92% for N1 to N3, and 84.51% for M1 staging; MMP-7 has a total accuracy of 81.69% for T1 to T4. The total accuracy of N1~N3 is 78.87%, the accuracy of M1 staging is 83.10%; the total accuracy of MMP-9 is 80.28% for T1~T4, the total accuracy of N1~N3 is 77.46%, and the accuracy of M1 staging is accurate The rate is 81.69%. At the same time, through serum testing, MMP-7 and MMP-9 in T4 stage patients are higher than those in other stages; MMP-7 and MMP-9 in N3 stage patients are higher than those in other stages; MMP-7 and MMP-9 in M1 stage patients are higher than M0 Period (P<0.05). ROC curve analysis showed that the AUC of FUS diagnosis for T staging was 0.741; the AUC for N staging was 0.748; the AUC for M staging was 0.695; the AUC of MMP-7 diagnosis was 0.681 for T staging; the AUC for N staging was 0.667 ; AUC for M staging is 0.643; MMP-9 diagnosis AUC for T staging is 0.720; AUC for N staging is 0.674; AUC for M staging is 0.636; AUC for T staging is 0.993 for combined diagnosis; N staging The AUC for M staging is 0.993; the AUC for M staging is 0.948, indicating that the combined diagnosis has a certain accuracy. Conclusion: Serum MMP-7 and MMP-9 expressions are closely related to gastric cancer staging, degree of differentiation, and depth of tumor invasion. Combined with FUS diagnosis, it can improve the accuracy of gastric cancer staging.