In order to study the influence factors on the pinned-pinned resonance of ballastless track rail, in this paper, based on the vibration calculation theory of periodically supported beam, the influence parameters of ballastless track on the pinned-pinned resonance of rail were analyzed by using the solid vibration analysis model established by FEM, and the sensitivity coefficients of those parameters were calculated through the single-dimensional sensitivity analysis method. The results show that the pinned-pinned resonance of rail is sensitive to the fastener span as the resonance frequencies vary remarkably with the increase of fastener span. Rail mass is a slightly sensitive parameter to the pinned-pinned frequency of rail, although its sensitivity coefficient is smaller than that of fastener span. The stiffness, damping of fastener and elastic modulus of track slab are all classified as insensitive parameters since they have little influence on the pinned-pinned frequency of rail. The constrained damper attached to the non-working surface of rail can reduce the vibration amplitude of the pinned-pinned resonance effectively, but hardly change the resonance frequencies. With the influence of fastener span, the pinned-pinned frequency of rail on ballastless track is lower than that on ballasted track.