A method for adjusting a transmit power in GSM, comprising: determining that a communications terminal concurrently executes services respectively on a first subscriber identity module, SIM, card and a second SIM card that are supported by the communications terminal, wherein the service executed on the first SIM card is a first service, the service executed on the second SIM card is a second service, a modem corresponding to the first SIM card is a first modem, and a modem corresponding to the second SIM card is a second modem; determining priorities of the first service and the second service according to the service type of the first service and the service type of the second service, wherein when the service type of the first service is a data service and the service type of the second service is a voice service, the priority of the second service is higher than the priority of the first service; configuring the first modem to use a first maximum transmit power limit, PLM1, to execute the first service; configuring the second modem to use a second low-level transmit power limit, PLL2, to access the second service; wherein PLM1 is greater than PLL2; adjusting the steady-state transmit power of the first modem to a fist low-level transmit power limit, PLL1, after the access of the second modem succeeds; wherein PLL1 is lower than PLM1; adjusting the steady-state transmit power of the second modem to a second maximum transmit power limit, PLM2; wherein PLM2 is greater than PLL2; wherein the steady-state transmit power of the second modem is greater than or equal to the steady-state transmit power of the first modem; wherein the steady-state transmit power refers to a transmit power of the voice service or the data service within a period of time starting from successful access of the voice service during execution of the data service to releasing of either of the voice service or data service; and increasing the transmit power of the first modem to the first maximum transmit power limit PLM1 after the second modem is released. determining that a communications terminal concurrently executes services respectively on a first subscriber identity module, SIM, card and a second SIM card that are supported by the communications terminal, wherein the service executed on the first SIM card is a first service, the service executed on the second SIM card is a second service, a modem corresponding to the first SIM card is a first modem, and a modem corresponding to the second SIM card is a second modem; determining priorities of the first service and the second service according to the service type of the first service and the service type of the second service, wherein when the service type of the first service is a data service and the service type of the second service is a voice service, the priority of the second service is higher than the priority of the first service; configuring the first modem to use a first maximum transmit power limit, PLM1, to execute the first service; configuring the second modem to use a second low-level transmit power limit, PLL2, to access the second service; wherein PLM1 is greater than PLL2; adjusting the steady-state transmit power of the first modem to a fist low-level transmit power limit, PLL1, after the access of the second modem succeeds; wherein PLL1 is lower than PLM1; adjusting the steady-state transmit power of the second modem to a second maximum transmit power limit, PLM2; wherein PLM2 is greater than PLL2; wherein the steady-state transmit power of the second modem is greater than or equal to the steady-state transmit power of the first modem; wherein the steady-state transmit power refers to a transmit power of the voice service or the data service within a period of time starting from successful access of the voice service during execution of the data service to releasing of either of the voice service or data service; and increasing the transmit power of the first modem to the first maximum transmit power limit PLM1 after the second modem is released.