超声对正常小儿硬脑膜下腔宽度的测定在国内、外尚未见报道；本文总结了２００例正常小儿硬脑膜下腔在超声下可见的宽度，得出新生儿、婴儿硬脑膜下腔宽度的正常超声测值。并将其与化脓性脑膜炎并发硬脑膜下腔积液患儿对比分析，总结出硬脑膜下腔积液穿刺治疗在超声下所显示的最小宽度的极限，为临床治疗提供参考。 Ultrasound on the determination of normal children’s subdural space width at home and abroad have not been reported; this paper summarizes the 200 cases of normal children’s subdural space in ultrasound can be seen under the width, obtained in neonates, infants, the normal subdural space width Ultrasound measurements. And compared with purulent meningitis in children with subdural effusion, the summary of the subdural effusion in the treatment of ultrasonically displayed the minimum width of the limit, provide a reference for clinical treatment.