We present a case of a child with a suprasellar arachnoid cyst and hydrocephalus who developed a massive traumatic epidural hematoma following a fall. This represents the first reported case of such a condition. The case is characterized by a progressive increase in hemorrhage leading to a massive hematoma, yet with relatively mild clinical symptoms. The hemorrhage originated from extensive blood seepage from the dura mater. Intraoperative hemostasis was challenging, and there was a large residual cavity of the epidural hematoma without repositioning of brain tissue after removal of the hematoma. Surgical measures such as extensive continuous compression hemostasis with Surgicel, the half-suspension technique, and continuous external drainage were employed to address these challenges. A second-stage surgery for the treatment of the suprasellar arachnoid cyst was performed 1.5 months after hematoma evacuation, utilizing neuroendoscopic ventriculocisternostomy (VCC). We recommend that for patients with traumatic brain injury and hydrocephalus, especially those with skull fractures or minimal intracranial hemorrhage, relying solely on clinical symptom observation and monitoring is insufficient. Timely and close monitoring with cranial CT is crucial for the early detection of progressive intracranial hemorrhage.