In order to overcome the limitations of traditional methods for measuring elastic modulus of the metal fiber, a novel method is proposed for measuring the elastic modulus of the metal fiber by vibration method．The measurement principle, apparatus, manipulation and error analysis were introduced. In this method, the measured metal fiber was generated in the form of a micro cantilever, and the cantilever can be vibrated for a short time when transient excitation is applied. The natural frequency of the cantilever can be used to calculate the elastic modulus of the material. Two kinds of materials, i.e. molybdenum wire and platinoiridium 25 fiber were tested in this work. The results prove that the measured values are consistent with that given in static tension method. The effect of beam length on determination of elastic modulus of materials was analyzed. The result shows that the influence of the ratio of L/d can be neglected only if the beam length is equal to or more than 8 times of the beam height (or diameter).