Abstract: Objective To explore the effect of bedside ultrasound guidance versus traditional touch method in the catheterization of dorsalis pedis artery in elderly critical ill patients in ICU. Methods A total of 72 elderly critically ill patients aged 65 years and above in ICU in our hospital were selected, and were carried out catheterization of dorsalis pedis artery and performed arterial pressure monitoring. They were divided into control group and experimental group by computer randomization software, with 36 cases in each group. The control group received traditional touch method for puncture and catheterization. In the experimental group, the catheter was placed under the guidance of ultrasound in the whole course at the bedside of ICU. The success rate of one-time catheterization, success rates of catheterization and puncture, catheterization time, accuracy rate of arterial pressure monitoring and incidence of complications of puncture sites were compared between the two groups. Results In the experimental group, the success rate of one-time catheterization was 86.11%, the success rate of catheterization was 100.00%, and the accuracy rate of arterial pressure monitoring was 100.00%, which were significantly higher than 63.89%, 80.56% and 83.33%, respectively in the control group(P<0.05); the average time of catheterization was(1.09±0.33)min, which was significantly shorter than(1.31±0.38)min in the control group(P<0.05); the incidence of complications in the experimental group was 5.56%, which was significantly lower than 25.00% in the control group(P<0.05). Conclusion Bedside ultrasound-guided catheterization of dorsalis pedis artery can effectively improve the success rate of catheterization and the accuracy rate of data dynamic monitoring, and reduce the incidence of complications such as hematoma and ecchymosis.