Although the resonance beam test method has advantages of accuracy and steady, there is great cost to manufacture and test a series of beam due to wide bandwidth and small interval which is acquired in experiment. To decrease number of beam in test of damping material,wave number method is introduced firstly to measure dynamic parameters of damping material to cut down the cost. This method, which based on the McDaniel method, tests complex wave number in unconstrained damping structure at first. Then, the wave number is substituted in equation of complex bending stiffness to get young’s modulus and loss factor. The experiment results and data tested by factory are compared to prove the accuracy of wave number method, it achieves the goal of decreasing consumption in test. The error enlarge factor is analyzed in process of young’s modulus and loss factor calculation, the simulation results show that the larger young’s modulus is, the test data is more accurate, the best ratio scale of damping layer and base layer is up to 5.