给出了直线结构的三原子分子振动的一个模型，该模型通过角簧实现弯曲振动模式.建立了该模型的振动微分方程 组.求解方程组得到了3 个本征振动频率和对应的振动模式.就二氧化碳、羰基硫和氰化氢3 个三原子分子，使用文献数据验 证了所给出的模型.结果表明按该模型的3 个振动频率与文献结果吻合良好.

A classic mechanics model is presented to account for the vibration of a linear triatomic molecule. In this model，a coil spring loops two chemical bonds. The coil spring possesses the potential energy in the bending mode，rather than the longitudinal spring along the bonds. The ordinary differential equation system of this model is formulated. By solving equation system，three eigenvibration frequencies and the corresponding modes are obtained.This model is validated by the literature data of three molecules，carbon dioxide，carbonyl sulfide and hydrogen cyanide. The results indicate that three eigenfrequencies of the presented model fit the literature data well.