Objective To explore the feasibility and guiding value of point-of-care ultrasound (PoCUS) in evaluating gastric residual volume (GRV) in the course of implementing enteral nutrition (EN) in patients with neurological critical illness. Methods Ninety patients with critical neurological diseases necessary for EN were admitted to the Department of Intensive Care Unit (ICU) of Taizhou Hospital of Integrated Traditional Chinese and Western Medicine from March 1, 2017 to September 30, 2018 were selected, and they were randomly divided into a GRV extraction group (control group) and a PoCUS GRV group (study group), 45 patients in each group. Both groups were fed with Ruidai nutrient solution by nasogastric pump at a rate of 18 hours per day to persistently administer the target feeding volume for consecutive 7 days. The differences in tolerance of EN, the incidence of feeding interruption, the daily volume of EN fluid, the ratio of reaching total enteral nutrition (TEN) and the levels of serum albumin (Alb), prealbumin (PA) and prognosis were compared between the two groups. Results The incidences of reflux and wrong aspiration in the study group were significantly lower than those in the control group [8.9% (4/45) vs. 24.4% (11/45) and 4.4% (2/45) vs. 17.8% (8/45), both P < 0.05]. The EN liquid volume, ratio of reaching TEN, Alb and PA levels in the study group were significantly higher than those in the control group [EN liquid volume (mL/d): 944.6±277.1 vs. 783.7±230.5, the ratio of TEN: 86.7% (39/45) vs. 68.9% (31/45), Alb (g/L): 30.6±3.0 vs. 29.4±2.4, PA (g/L): 280.5±31.8 vs. 267.7±28.4, all P < 0.05]. The incidence of diarrhea [15.6% (7/45) vs. 13.3% (6/45)], the incidence of feeding interruption [8.9% (4/45) vs. 13.3% (6/45)], the length of stay in ICU (days: 10.4±6.2 vs. 8.3 ±5.4), the mortality [8.9% (4/45) vs. 13.3% (6/45)] had no significant differences between the two groups (all P > 0.05). Conclusion Evaluating GRV by PoCUS to adjust EN implementation plan can reduce the incidences of reflux and wrong aspiration and increase the EN intake.