Objective To improve the success rate of cerebrospinal fluid (CSF) collection in rats using a modified suction device with negative pressure. Methods A flow regulator was added to the original apparatus to adjust the intensity of negative pressure and to limit the volume of CSF collected each time. A total of 36 male Sprague?Dawley (SD) rats were randomly divided into 3 groups, and the CSF was collected in 3 ways: drawing from the cerebellomedullary cistern via percutaneous puncture, using a suction device with negative pressure and using a modified device. Kruskal?Wallis test was used to evaluate the differences in result between these three methods. Results The modified suction device with negative pressure effectively reduced bleeding. The quality of CSF collected with it was 75% of 12 rats,significantly higher than that obtained with the original device (33.3%, P < 0.01) or drawn from the cerebellomedullary cistern via percutaneous puncture (0%, P < 0.001). The success rate of qualified sample collection was highly superior to those of previously reported CSF collection methods. Conclusions Our modified suction device for CSF collection is simple and user?friendly, with minimal damage and little bleeding to rats. It can obviously improve the success rate of CSF collection in rats.