Objective To investigate the effect of nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2) on energy metabolism reprogramming of multiple myeloma (MM) cells by interfering with phosphatidylinositol 3 kinase/protein kinase B (PI3K/AKT) signal pathway mediated by reactive oxygen species (ROS). Methods The bone marrow blood of 50 patients with MM and 29 healthy controls were collected from April 2019 to April 2022. The relative expressions of NOX2, PI3K in bone marrow blood and the level of NOX2 in MM cell line U266 and LP-1 were detected by qRT-PCR. To analyze the correlation between the expression levels of NOX2 and PI3K, NOX2 and clinicopathological features. Detection of PI3K/AKT signal pathway related molecules expression in U266 and LP-1 cells by WB. Detection of 〖HJ46x〗ROS level in cells by 2',7'-dichlorofluorescin diacetate (DCFH-DA) fluorescence probe. 2-［N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino］-2-deoxyglucose (2-NBDG) was used to detect the glucose uptake of cells. Detection of lactic acid secretion was applied by biochemical experiment. Detection of cell metabolism was applied by Seahorse. Cell proliferation, migration, invasion and tumorigenesis were detected by CCK-8, EdU, scratch, Transwell and xenotransplantation in vivo. Immunohistochemical detection of NOX2, PI3K/AKT signal pathway and glycolysis related molecule expression in transplanted tumor.Results The expression of NOX2 increased in bone marrow blood of MM patients and MM cell line. The results of correlation analysis showed that there was a positive correlation between the expression level of NOX2 and PI3K in bone marrow blood of MM patients, and the expression level of NOX2 was correlated with ISS stage, β2-microglobulin and Durie-Salmon stage. Compared with NC group and sh-NC group, the expression of p-PI3K and p-AKT in U266 and LP-1 cells increased in NOX2 group (P＜0.05), while p-PI3K and p-AKT expression decreased in sh-NOX2 group (P＜0.05). Compared with NC group, ROS level, 2-NBDG fluorescence intensity, lactic acid secretion, extracellular acidification rate, glycolysis ability, proliferation, migration and invasion ability of U266 and LP-1 cells NOX2 group increased (P＜0.05), the volume and mass of transplanted tumor increased (P＜0.05), and the expression levels of lactate dehydrogenase A (LDHA), 3-phosphoinositide-dependent protein kinase-1 (PDK1), p-PI3K and p-AKT increased (P＜0.05).Conclusion NOX2 is highly expressed in bone marrow blood and cell lines of MM patients, which may promote the development of MM by promoting ROS production and activating PI3K/AKT signal pathway, promoting energy metabolism reprogramming and malignant biological behavior of MM cells