Starting from the energy conversion and energy conservation law in the constant-NVE ensemble, the molecular dynamics method using the COMPASS force field was applied to investigate the dynamic properties of graphene nanoribbons (GNRs) together with the GNR-based strain sensors. The following results were obtained: (a) the nonlinear response dominates the dynamic behavior of GNRs, and their ultra-high fundamental frequencies are closely related with the length and boundary conditions; (b) the effect of uniaxial tensile strain on the fundamental frequencies of GNRs is significant and strongly depends on boundary conditions, and the GNR-based strain sensor clamped on four edges has a higher frequency shift, and its sensitivity is up to 7800 Hz / nanostrain, much higher than that of carbon nanotube-based strain sensor with the same length; (c) the resonant characteristics of GNRs and GNR-based strain sensors are insensitive to the chirality. The obtained results suggest that, through cutting the appropriate size and setting the boundary conditions, the GNRs could be used to design a new generation of nanoelectromechanical system (NEMS) resonators and strain sensors, owing to their ultra-low density and ultra-high fundamental frequencies as well as ultra-high sensitivity without considering the impact of chirality.