针对目前小儿上气道内流场特性分析较少且实验验证困难等问题，本文基于3D打印技术构建了小儿上气道内流场特性分析的实验平台，实验结果与临床鼻阻力实验的最大误差为11.1%，可为小儿上气道内流场特性的理论分析提供一种直观简便、准确可靠的实验方法。在此基础上，探索了不同程度的扁桃体肥大对内流场特性的影响作用。研究结果表明，当口咽部狭窄度达到56%以上（扁桃体肥大为临床III度），上气道吸气气流将发生急剧变化，流速和流阻增大，通气量下降，内流道出现较大的逆压梯度及内外压差，为患儿夜眠憋气、呼吸暂停、打鼾等症状提供了直观的理论依据，也为临床医生开展扁桃体手术干预和术后恢复方案的制定提供了重要的参考。

Aiming at the problems of limited analysis and difficult validation on flow characteristics of children upper airway, this paper presents an experimental bench using upper airway models manufactured by 3D printing technology to study these problems. The maximum difference between experimental results and clinical nasal resistance test is 11.1%, which proves the experimental method based on 3D printing technology is reliable and accurate, and it can be a direct and easy method for the research of flow characteristics of children upper airway. After that, the effect of different levels of hypertrophy of tonsil on flow characteristics is studied. It is found that, when the narrow level of oropharynx reaches 56%, where the level of hypertrophy of tonsil reaches III degree, flow characteristics of upper airway will obviously change, in terms of increasing flow velocity and resistance, decreasing flow volume, and a large inverse pressure and pressure difference in oropharynx, which can an explanation of the symptoms for OSAHS child, and also will be a significant reference to clinicians on tonsillectomy operation and its postoperative recovery plan.