Objective Alzheimer's disease (AD) has been confirmed to be associated with cholesterol metabolism in recent years. However, the efficacy of statins against AD remains controversial. This paper aims to systematically review the efficacy and safety of statins combined with conventional therapy in the treatment of AD by meta-analysis, and to provide a reference for clinical application of statins in the treatment of AD.Methods Two researchers independently conducted searches for literature on statins and AD in databases including CNKI, WanFang Data, VIP, China Biology Medicine disc, PubMed, and SCI. After screening and quality evaluation, the articles were meta-analyzed using Revman 5.3 software.Results A total of 8 articles involving 8 randomized controlled trials and 609 patients were finally included. In those patients, 304 received statins combined with conventional therapy, while 305 were used as control. Compared with the control group, the treated patients had significantly improved scores for mini-mental state examination (mean difference [MD]=1.30, 95% confidence interval [CI]: 0.70-1.90, P<0.001) and activities of daily living (MD=-5.28, 95%CI: -7.61 to -2.96, P<0.001). There was no significant difference in incidence of adverse events between the two groups (risk ratio=1.82, 95%CI: 0.37-8.99, P=0.46).Conclusions Conventional therapy combined with statins can further improve the performance of cognitive function and activities of daily living in AD patients without increasing the incidence of adverse reactions.