Objective To explore the disinfection effect and drying time of dosing port disinfection with 75% ethanol at different spray volume, so as to choose suitable spray volume. Methods Totally 200 penicillin bottles of the same batch were selected and randomized into a control group, an experimental group A, an experimental group B and an experimental group C, with 50 bottles in each group. The control group was disinfected by wiping with 75% ethanol, and the experimental group was disinfected by spraying with 75% ethanol. Each penicillin bottle was disinfected once, the single spray volume of the experiment group A, B and C was 0.10 mL, 0.13 mL and 0.16 mL respectively. The drying time of each penicillin bottle after disinfection was recorded, and samples were collected for culture of bacteria.Results No bacteria were detected in the four groups, the qualified rate was 100%. The drying time of the control group and the experimental group A, B, and C was (77.82±13.02) s, (61.76±8.26) s, (69.60±8.84) s and (78.62±8.46) s respectively. There were significant differences between each two groups (P<0.01 for all) except for the control group and the experimental group C (P>0.05).Conclusion Selection of a single spray of 75% ethanol at around 0.13 mL for dosing port disinfection in pharmacy intravenous admixture service, can guarantee disinfection effect and reduce drying time, then improve working efficiency.