Bridge frequency is an important parameter reflecting the structural characteristics of a bridge. Using a vehicle equipped with an acceleration sensor to pass over the bridge for frequency identification avoids the inefficiencies, complexity, and high costs associated with installing sensors directly on the bridge. By installing a lightweight ‘ single-axis cantilever amplifier’ with a rigid cantilever on the crossing vehicle and combining it with Fast Fourier Transform (FFT), the visibility of bridge frequencies can be significantly improved. The effects of different parameters on bridge frequency identification are discussed. The results show that: the resolution of bridge frequency decreases as vehicle speed increases; increasing the cantilever length is beneficial for bridge frequency identification; vehicle damping has little effect on bridge frequency identification; road surface roughness is unfavorable for frequency identification, but after introducing multiple vehicle excitations, the first few bridge frequencies can be identified; due to the energy dissipation from the bridge damping, the acceleration amplitude corresponding to the first few identified bridge frequencies is significantly reduced, yet the effect of the single-axis cantilever amplifier remains obvious.