The vibration of a cracked beam due to a moving mass is investigated by using the moving finite element method and the local flexibility method. The effect of the relative position and relative depth of the crack on the natural frequency and the dynamic response of the cracked beam under different velocity are discussed through the numerical calculation. The analysis shows that the crack and the moving mass increase the dynamic displacement of beam, but decrease the coupling frequency of the system in a certain degree. Meanwhile, with the increase of the speed of moving mass and the relative depth of crack, the dynamic response of the beam is apt to increase.