Background. Insect drugs have great potential for treating cardiovascular diseases. Xinmailong (XML) injection, a bioactive composite extracted from Periplaneta americana (a species of cockroach), was wildly used in treating heart failure in China. This meta-analysis aimed to assess the efficacy and safety of XML injection for the improvement of cardiac function in HF. Materials and Methods. Online literature search for relevant studies was performed using databases including PubMed, EMBASE, Cochrane Library, CNKI, and Wanfang. Left ventricular ejection fraction (LVEF), six-minute walk test (6MWT), and brain natriuretic peptide (BNP) were selected as target outcomes. The analysis was performed using Stata 12.0, and sources of heterogeneity were explored by subgroup analysis and metaregression. Results. 32 studies were included in this meta-analysis after meeting the inclusion/exclusion criteria. The results demonstrated that additional use of XML improved LVEF (WMD = 5.82, 95% CI: 5.52–7.13, P