Background: Endoscopic surgery for colorectal tumors often involves CO2 pneumoperitoneum and a supine head-down position, which may increase the risk of cerebral hypoxia, edema, stroke, and postoperative cognitive dysfunction, particularly in elderly athletes whose vascular health may already be compromised by age and physical stress from long-term sports participation. Protecting brain function during and after surgery is thus crucial for maintaining postoperative cognitive and physical performance levels in this population. Objective: This study aims to evaluate the effects of Remimazolam Tosilate on brain protection and cognitive function in elderly athletes undergoing endoscopic surgery for colorectal tumors, assessing its efficacy and safety compared to traditional anesthetics. Methods: From July 2021 to October 2022, sixty elderly athletic patients diagnosed with colorectal tumors were randomly divided into three anesthetic groups at our hospital. These included a Sevoflurane group (Sevoflurane + Fentanyl induction + Remifentanil maintenance), a Propofol group (Propofol + Fentanyl induction + Remifentanil maintenance), and a Remimazolam Tosilate group (Remimazolam Tosilate + Fentanyl induction + Remifentanil maintenance), with twenty patients in each group. We compared early brain function injury indices, clinical examination outcomes, and cognitive functions across the groups. Results: Measurements such as serum neuron-specific enolase (NSE), S100 protein, myelin basic protein (MBP), arterial and jugular bulb oxygen partial pressures, carbon dioxide levels, hemoglobin content, oxygen saturation, blood glucose, and lactic acid levels indicated that the Remimazolam Tosilate group experienced better outcomes than those receiving Sevoflurane or Propofol. Conclusion: Remimazolam Tosilate offers significant neuroprotective benefits during endoscopic colorectal surgery in elderly athletes, enhancing postoperative cognitive function and potentially facilitating quicker cognitive and physical recovery. This study underscores the importance of tailored anesthetic approaches to support the unique needs of elderly athletes undergoing significant surgical interventions.