ObjectiveTo explored the accuracy and effectiveness of “swimming pool” sign in recognizing fluid attenuated inversion recovery sequence (FLAIR) compared with traditional methods, and to solve the difficulties in distinguishing T1 weighted image (TIWI) and FLAIR in clinical medical students and junior residents. Methods Using the observational research method, forty standardized training physicians who rotated in the Department of Neurology, West China hospital of Sichuan University were included as the research objects between September and November 2021. Standardized training physicians were randomly divided into “swimming pool” sign group and control group, with 20 persons in each group. In the same period, 100 patients with central nervous system infection, cerebral vascular disease, dementia syndrome, multiple sclerosis and no obvious intracranial lesions were selected from the Department of Neurology, West China Hospital of Sichuan University between September and November 2021. According to the diagnosis, the patients were divided into 5 groups with 20 cases in each group. Two groups were given the same 20 images respectively, including T1WI and FLAIR. Record the accuracy, total time-consuming and time-consuming per image of each standardized training physicians. Results Each patient had “swimming pool” sign. Under different backgrounds, the accuracy of the “swimming pool” sign group was higher than that of the control group (P<0.001), while the total time-consuming and time-consuming per image were lower than that of the control group (P<0.001). Conclusions In different nervous system diseases, “swimming pool” sign is stable on FLAIR. Compared with traditional methods, “swimming pool” sign can quickly and accurately distinguish T1WI and T2 FLAIR.