Objective To investigate the effect of applying standard ultrasound atlas assisted four-step positioning method in nasoin-testinal intubation for ICU patients. Methods A total of 100 ICU patients who needed an indwelling nasointestinal tube were selected and evenly divided into 2 groups by chronological order. The control group received nasointestinal intubation by using conventional blind insertion method, while the intervention group received the procedure by the standard ultrasound atlas assisted four-step positioning method. The rate of nasointestinal tube passing through pylorus at the first attempt, the time to successful placement at the first attempt, and the incidence rate of complications during the procedure, were compared between the two groups. Results The intervention group had significantly higher rate of nasointestinal tube passing through pylorus at the first attempt, and significantly shorter time to successful placement at the first attempt than the control group (all P＜0.05). The former group also had lower incidence rate of complications during the procedure than the controls, though the difference between the 2 groups was not significant. Conclusion The standard ultrasonic atlas assisted four-step positioning method had higher success rate of nasointestinal intubation than blind insertion method. It also has shorter operation time and fewer complications, and can be used as an effective way to establish early enteral nutrition support for severe patients.