In nuclear power Ultrasonic nondestructive detection, because of the wide detection range and more probes, the amount of the acquireddata are reserved. Therefore, the design of data compression system plays an important role in ultrasonic nondestructive detection application in nuclear power. Methods of existing data compression are studied. Transferring the signal to be compressed from the one-dimensional space to two-dimensional space are presented. And then it carries out two-dimensional wavelet compression, realizes the two-dimensional signal and spatial signals compression. It analyses and compares with a one-dimensional compression of the signal. Experimental results prove that this scheme of the algorithm is effective.