Abstract: It is important to control the effective strengthening depth in the dynamic consolidation of collapse loess roadbed. The consolidation effect was evaluated by analyzing the data of vibration wave from the field test and deducing the formula of strengthening depth. The parallel test of the roadbed strength after consolidation was done by gravity reconnaissance. The better consistency of the derived formula of strengthening depth with the empirical formula proves it is a new and effective method to control the consolidation effect by vibration measurement.