采用流体模型对圆筒内表面PIII过程进行了二维数值模拟 ,研究了筒内鞘层扩展和交叉重叠对内表面注入的注入能量和注入剂量的影响 .通过模拟发现 ,内表面注入过程存在注入能量和注入剂量偏低的问题 ,但前者并不十分严重 ,而后者则比较严重 .在鞘层发生交叉重叠后筒内出现的高能离子流对注入能量和注入剂量偏低的问题有改善作用 The fluid model was used to simulate the PIII process on the inner surface of the cylinder, and the effects of expansion and cross-overlap of the inner sheath on the injected energy and the injected dose on the inner surface were investigated. Energy and injection dose is low, but the former is not very serious, while the latter is more serious in the sheath after cross-overlap occurred in the tube of high energy ion flow on the injection of energy and injection of low dose to improve the role of the problem