目的　观察盐酸苯环壬酯 (PCH)对空晕病易感飞行学员脱敏习服的影响以及停药后有无反弹现象。　方法　经阶梯式累加科里奥利加速度刺激评定为空晕病易感者的 18名飞行学员为受试对象 ,以 Graybiel急性运动病诊断标准 M 为终点的科里奥利加速度耐受值为评定指标。 18名飞行学员随机分为两组 ,服用 PCH组和服用安慰剂组。两组飞行学员都接受以科里奥利加速度为刺激源的脱敏习服训练。PCH(3mg)和安慰剂分别在训练前 1h口服。观察两组脱敏训练过程的差别 ,并在 PCH停药后连续 3d测试有无反弹现象。　结果　 PCH可明显加速脱敏习服训练过程 ,停药后未见科里奥利加速度耐力下降和易感性反弹现象。　结论　 PCH具有加速脱敏习服训练过程的作用 ,而没有东莨菪碱停用后易感性反弹的类似效应出现 Objective To observe the effect of phencynonate hydrochloride (PCH) on the desensitization abilities of students who were susceptible to the flying sickness and whether there was any rebound after discontinuation. Methods Eighteen flight students assessed by stepwise Coriolis acceleration stimuli as subjects with susceptibility to SLE were enrolled in this study. Coriolis acceleration tolerance values ​​based on Graybiel Acute Motor Disease Diagnostic Criteria M index. Eighteen pilots were randomly assigned to receive either PCH or placebo. Both flight crew members received desensitization training with Coriolis acceleration as the stimulus. PCH (3mg) and placebo were orally administered 1h before training. Observed the difference between the two groups of desensitization training process, and in the PCD after stopping for 3 days to test whether the rebound phenomenon. Results PCH could obviously accelerate the process of desensitization and acclimatization training, and Coriolis acceleration endurance decline and susceptibility rebound were not observed after stopping treatment. Conclusions PCH has the effect of accelerating the process of desensitization attendant training without the similar effect of susceptibility oto-rebound after discontinuation of scopolamine