The "frequency hopping" phenomenon often occurs when using the wavelet packet transform to process non-stationary seismic signals. To solve this problem, we examine the relationship between the order number of the wavelet packet tree bands and the order number of the nodes, based on the wavelet packet transform and exclusive or (XOR) operation algorithm. We clarify the arrangement rule between the frequency bands of the signal subspace and the tree nodes of the wavelet packet. Moreover, we propose a conversion algorithm for seismic signals from the order number of the nodes to that of the frequency bands. Based on the MATLAB platform, we use the Tangshan wave (NS direction) as an example and verify the correctness of the algorithm.