Objective To discuss the effect of silencing Forkhead box K1 （FOXK1） on the proliferation， migration， and invasion of the gastric cancer HGC-27 cells， and to clarify the possible mechanism. Methods The expression levels of FOXK1 mRNA in gastric cancer tissue and normal gastric tissue were consulted based on the Gene Expression Profiling Interactive Analysis （GEPIA） Database； the synthetic si-FOXK1 was used to transfect the gastric cancer HGC-27 cells in vitro， and the cells were divided into blank control group， nc-FOXK1 group， and si-FOXK1 group. Western blotting method was used to detect the transfection efficiencies of the cells in various groups； MTT assay was used to detect the proliferation abilities of the HGC-27 gastric cancer cells in various groups after transfected with si-FOXK1. The clone formation assay was used to detect the number of clone-forming of the HGC-27 gastric cancer cells after transfected with si-FOXK1；wound healing assay was used to detect the migration rates of the gastric cancer HGC-27 cells in various groups after transfected with si-FOXK1；Transwell chamber assay was used to detect the numbers of migration and invasion cells in various groups；Western blotting method was used to detect the expression levels of NF-κB pathway-related proteins ［nuclear factor κB p65 （NF-κB p65） and phosphorylated NF-κB p65 （p-NF-κB p65）］ in the gastric cancer HGC-27 cells in various groups after transfected with si-FOXK1. Results The GEPIA Database results showed that compared with normal gastric tissue， the expression level of FOXK1 mRNA in gastric cancer tissue was increased （P<0.05）. The Western blotting method results showed that the expression level of FOXK1 protein in the gastric cancer HGC-27 cells was higher than that in normal gastric mucosal GES-1 cells （P<0.01）. Compared with blank control group and nc-FOXK1 group， the expression level of FOXK1 protein in the cells in si-FOXK1 group was significantly decreased （P<0.01）. The MTT assay results showed that compared with blank control group and nc-FOXK1 group，the proliferation ability of the gastric cancer HGC-27 cells in si-FOXK1 group was decreased （P<0.05）. The clone formation assay results showed that compared with blank control group and nc-FOXK1 group， the number of clone-forming of the gastric cancer HGC-27 cells in si-FOXK1 group was decreased （P<0.05）. The cell scratch healing results showed that compared with blank control group and nc-FOXK1 group， the migration rate of the gastric cancer HGC-27 cells in si-FOXK1 group was decreased （P<0.05）.The Transwell chamber assay results showed that compared with blank control group and nc-FOXK1 group， the number of invasion cells of the gastric cancer HGC-27 cells in si-FOXK1 group was decreased （P<0.05）. The Western blotting results showed that compared with blank control group and nc-FOXK1 group， the expression level of p-NF-κB p65 protein in the cells in si-FOXK1 group was decreased （P<0.05）. Conclusion FOXK1 is highly expressed in the gastric cancer HGC-27 cells， and silencing FOXK1 can inhibit the proliferation， migration， and invasion abilities of the HGC-27 gastric cancer cells； its mechanism is possibly associated with the NF-κB pathway.