Experiments on continuous rotating detonation wave of H₂/air were performed with constant air mass flow rate and varied H₂/air equivalence ratio(ER). Three different propagation modes of the continuous rotating detonation wave were found as the decreasing of ER, namely, one direction mode at high ER from 0.90 to 1.86, two-wave collision propagation mode at low ER of about 0.75, hybrid mode of one direction mode and two-wave collision propagation mode at middle ER. The propagation characteristics of the high-frequency pressures were analyzed and the mode transition mechanism of continuous rotating detonation wave was preliminarily studied. With a higher ER, the strength of the detonation wave is increased and the loss and velocity deficit during the propagation are relatively small, and the continuous rotating detonation wave can be sustained in the one direction mode; while with a lower ER, the strength of the continuous rotating detonation wave is reduced and the influence of the loss and velocity deficit during the propagation is relatively enlarged, only in the two-wave collision propagation mode can the continuous rotating detonation wave be sustained. This can be attributed to the collision of the two counter-propagating shock waves in the two-wave collision propagation mode, which will promote the heat release, will enable the continuous rotating detonation wave to propagate steadily at a low ER, and will make the two-wave collision propagation mode possibly be the ultimate propagation mode of continuous rotating detonation wave. 