Abstract: The characteristics of premixed gas detonation wave propagating in two tubes with diameter,20 mm and 60 mm respectively,were investigated.Primarily,the detonation wave pressures and velocities were measured,and the mixture pressure, concentration,equivalence ratio,and the dimension of connection tube were considered in the study.It was found that the detonation could appear in the bigger tube even when the detonation was not triggered in the smaller tube.The connection tube with smaller diffusion angle is favorable for detonation re-triggering.The pressure and velocity of re-triggered detonation are affected by mixture pressure,concentration, and equivalence ratio.