Objective In order to explore the role of long non-coding RNA SNHG12 in hepatitis B virus X protein (HBx) induced hepatocarcinogenesis. Methods The liver precursor cells 14-19, EGFP-14-19 and HBx-EGFP-14-19 constructed by the research group was injected into the body through the hepatic portal vein of KM mice; qRT-PCR and Western blot were used to detect the mRNA and protein expression of HBx, SNHG12 and downstream regulatory genes in liver tissues of 30 d, 90 d, 180 d and 360 d mice and cell models. Si-SNHG12 was used to interfere with SNHG12 expression in vitro, the mRNA and protein expression of SNHG12 and downstream genes were detected, and its effect on phenotype in vitro was observed by CCK-8, flow cytometry, scratch test and transwell test. HE staining was used to observe the liver sections of mice. Results qRT-PCR showed that SNHG12, Notch1 and Hes1 were up-regulated in HBx overexpression cells and mouse liver tissue at each time point (F=48.808,P<0.000 1;F=13.322,P<0.000 1); the results of Western blot showed that in HBx over-expressing cells and animal models, the expression of SNHG12 was increased induced by HBx, resulting in the activation of Notch1 signal pathway, the down regulation of pro-apoptotic factor Bax, anti-apoptotic factor Bcl-2, and the up-regulation of cell cycle factors CDK2, cyclin E. After inhibiting the expression of SNHG12, the results of qRT-PCR and Western blot showed that SNHG12 (t=22.746,P<0.000 1) and the above genes were inhibited; CCK-8 experiment showed that cell proliferation was significantly inhibited, flow cytometry showed that cell apoptosis increased, scratch experiment and transwell experiment showed that cell migration and invasion decreased. Conclusions HBx induced Notch1 expression by up regulating SNHG12, resulting in abnormal cell proliferation, cycle and apoptosis, so as to promote the occurrence of liver cancer.