Objective To investigate the effect and mechanism of miR-16-5p on pyrolysis of rat normal liver cell line BRL-3A induced by hypoxia-reoxygenation. Methods An in vitro model of hepatic ischemia reperfusion injury was established by cellular hypoxia-reoxygenation and the pyrolysis rate was measured by flow cytometry. RT-qPCR was used to measure the expression level of miR-16-5p. Overexpressed miR-16-5p in cells by miR-16-5p mimics was used to examine the effect of miR-16-5p on pyrolysis. Western blot was used to measure protein expression levels of pyrolysis-related proteins caspase 1, IL-1β, and IL-18. The relationship between miR-16-5p and NLRP1 was predicted through bioinformatics analysis and dual luciferase reporter gene assays. Interference and overexpression of NLRP1 were performed to investigate the effect of NLRP1 and the miR-16-5p / NLRP1 axis on pyrolysis. Results Compared with the blank control group, the pyrolysis rate of the model group was increased significantly ( P< 0. 01) and expression of miR-16-5p was decreased significantly (P<0. 05). Overexpression of miR-16-5p significantly decreased the pyrolysis rate (P<0. 01) and inhibited the expression of caspase 1, IL-1β, and IL-18 (P<0. 01 or P<0. 05). The dual luciferase reporter gene assay showed that NLRP1 was a target gene of miR-16-5p. Overexpression of miR-16-5p significantly reduced the mRNA and protein levels of NLRP1 (P< 0. 01 or P< 0. 05). Additionally, overexpression of NLRP1 reversed the inhibitory effect of miR-16-5p on pyrolysis (P<0. 01) and the inhibitory effect on the expression of caspase 1, IL-1β, and IL-18 (P<0. 01 or P<0. 05). Conclusions MiR-16- 5p inhibits expression of caspase 1, IL-1β, and IL-18 by targeting NLRP1, thereby improving pyrolysis of BRL-3A cells caused by hypoxia-reoxygenation.