Abstract: To explore the critical factors influencing the results of microtremor-based exploration at a depth of thousands of meters, this study conducted experiments using triangular arrays based on spatial autocorrelation(SPAC) and extended SPAC(ESPAC).Focusing on factors such as array size, acquisition unit frequency, and acquisition duration, this study explored the frequency band ranges corresponding to different array sizes, the arrangement of arrays in kilometer-depth exploration for obtaining both deep and shallow data, and the improvement in deep resolution.Based on the analysis and discussion results, this study established a parameter-setting system to improve the accuracy of exploration at a depth of thousands of meters.