Objective To analyze the effects and mechanisms of a disintegrin and metalloproteinase with thrombospondin motifs 14 (ADAMTS14) gene in gastric cancer associated with Helicobacter pylori (Hp) infection and explore the potential of ADAMTS14 as a novel target for biological therapy of gastric cancer. Methods The Caner Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases were utilized to analyze differentially expressed genes in gastric cancer tissues and Hp-positive gastric mucosa, and to screen potential targets. For the selected target ADAMTS14, its expression pattern in gastric cancer and Hp-positive gastric mucosa was analyzed. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was performed on the genes co-expressed with ADAMTS14 in gastric cancer. Kaplan-Meier Plotter database was used to analyze the correlation between high- and low-ADAMTS14 expression and prognosis of gastric cancer patients. The expression of ADAMTS14 and its relationship with clinicopathological features in 30 patients with gastric cancer were analyzed using real-time fluorescent quantitative PCR (RT-qPCR) and immunohistochemistry. The relationship between Hp infection and ADAMTS14 expression was analyzed using GEO database, and confirmed by cell line infection experiment. ADAMTS14 expression in gastric cancer cell line NCI-N87 was silenced by small interfering RNA to analyze its effect on the function of gastric cancer cells; The effect of ADAMTS14 knockdown on downstream target genes of Hippo signaling pathway was analyzed by RT-qPCR and Western blotting. Results A total of 16 genes closely related to Hp infection and gastric cancer were identified by analyzing the TCGA and GEO databases. According to TCGA database, the ADAMTS14 expression in gastric cancer tissues was higher than that in healthy gastric mucosa (P<0.0001). RT-qPCR and immunohistochemistry results also showed higher ADAMTS14 expression in gastric cancer tissues compared to adjacent tissues (P<0.01). Survival analysis demonstrated poor prognosis in patients with high ADAMTS14 expression (P<0.001). Data from GSE60427 showed that ADAMTS14 expression was upregulated in Hp-infected gastric mucosa and cell lines (P<0.001). After Hp P12 infection, the ADAMTS14 expression in NCI-N87 cells was higher than that in uninfected group. ADAMTS14 knockdown significantly inhibited the proliferation and migration of NCI-N87 cells (P<0.05), and it also significantly inhibited the expression of Hippo signaling pathway target genes, including BMP7, BMPR2, FZD4, PARD3 and SAV1 (P<0.05). Conclusion ADAMTS14 is highly expressed in Hp-positive gastric mucosa and gastric cancer tissues, which may accelerate gastric cancer progression by regulating Hippo signaling pathway, and holds potential as a new marker and therapeutic target for Hp infective gastric cancer.