To investigate the difference in clinical efficacy and safety of different meropenem regimens on patients with serious infection in ICU. Then, 228 patients with serious infection in ICU were divided by random into control group (intermittent administration in 1000mg/30min single dose) and research group (continuous administration in 200mg/10min +800mg/180min), respectively. The blood concentration of meropenem were recorded in two groups at different time points, and difference in treatment effectiveness, iconographic effectiveness, bacterial eradication rate, 28-day survival rate and many other clinical scoring indices (SOFA, APACHEII, CPIS, and SIRS) were compared between two groups. There were 212 patients completing the whole research, including 104 patients in research group and 108 patients in control group. The difference in treatment effectiveness (77.8% vs 53.7%), iconographic effectiveness (51.0% vs 18.5%), and 28-day survival rate (86.5% vs 64.8%) between two groups performed statistical significance (P<0.05). However, the difference in bacterial eradication rate (48.0% vs 46.3%) performed no statistical significance. Eight hours later, the difference in average blood concentration between two groups (9.61±3.63μg/ml vs 1.5±0.51μg/ml) showed statistical significance. Moreover, the difference in clinical scoring indices except APACHE II score between two groups performed statistical significance. It was helpful to maintain the blood concentration of meropenem by extending the transfusion time. Therefore, it could increase the clinical cure rate and 28-day survival of patients with serious infection in ICU, improve clinical indices, and reduce the usage amount of antibiotics.