In the paper

basic equation of finite element dynamics analysis for double circular arc gear tooth is given. The method for choosing boundary condition and distance between node points is discussed. The effect of module、 helix angle、face width、number of teeth and thickness of nave collar on proper freuqency is analyzed. we obtain follow consulation: If the point at nave collarsection is fixed and shape of elements is harmonious.the finite element method may be used in solving vibration freqency and model of double circular arc gear tooth. Main parameters effecting intrinsic attributes of geartooth is helix angle 、face width and module. The effect of nave collar and number of teeth is weak.