文章重点讨论了推力和空气阻力对火箭横向振动频率和振型的影响，分析了在推力和阻力作用下频率降低的原因，给出了推力对振型频率影响的估计式。发动机喷管与火箭固联时的横向运动方程式及其相应的边界条件是分析工作的基础。文中得到的主要结论适用于主动加速段、被动减速段和推力与阻力平衡时的巡航段。在小推力和小轴向过载的情况下，各种不同的计算方法所得的结果相差不大。在大推力和高过载情况下，不同的近似解与精确解的差别可能是很大的。

In this paper, the influence of thrust and air drag on rocket lateral vibration is studied, and the frequency reduction under the thrust and drag is analyzed. The formulas for evaluation of the changes of frequencies and vibration modes are obtained. The equations of transverse movement when nozzle connected rigidly with rocket and related boundary conditions form the basis for analyses. The conclusions obtained are applicable for active accelerating and passive decelerating parts of trajectory as well as the cruise flight when thrust and drag are balanced. The analyses show that for small thrust and small axial overload, the discrepancy resulted from different calculation methods is not big, whereas for the heavy overloaded case a more accurate solution is extremely necessary.