To investigate rapamycin's effect on high-glucose induced podocyte injury and its related mechanism, human glomerular podocytes (HGPC) were cultured in vitro. The cells were divided into control group, model group, rapamycin group, inhibitor group, rapamycin + inhibitor group and rapamycin + activator group. Podocyte morphology, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) levels, cell proliferation rate, apoptosis rate, NOD-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein (ASC), cysteine aspartate protease-1 (Caspase-1) mRNA, protein and p38 mitogen-activated protein kinase (p38 MAPK) pathway key protein expression levels were observed. Compared with the control group, the cell arrangement was loose, the cell septum increased, and the cell proliferation rate decreased in the model group (P<0.05), and the levels of TNF-α and IL-1β, apoptosis rate, NLRP3, ASC, Caspase-1 mRNA and protein, and p-p38 MAPK protein increased (P<0.05). Compared with model group, the above cell states and indexes were improved in rapamycin group and inhibitor group (P<0.05). Compared with the rapamycin group, the above cell status and indexes were further improved in the rapamycin + inhibitor group (P<0.05), whereas the opposite was observed in the rapamycin + activator group (P<0.05). Rapamycin can improve the morphology of high glucose induced podiocytes by inhibiting p38 MAPK signaling pathway, promote cell proliferation, inhibit cell apoptosis, inflammatory release and activation of NLRP3 inflammasome, could provide reference for the study of diabetic nephropathy.