A method of selecting an active SIM from multiple SIMs and a wireless device utilizing the same are disclosed. The method includes: acquiring SIM information associated with each SIM under a dynamic environment, wherein each SIM provides for the PS data service; calculating a SIM score of each SIM based on the acquired SIM information associated with each SIM; and selecting the active SIM based on all SIM scores to provide for the PS data service. The SIM information includes RSSI, RSCP, Ec/N0, CQI, and data speed on each SIM in the dynamic environment.