A narrow band internet of things, NB-IOT, based device group access method, comprising: establishing, by a device management module of an NB-IOT based device group access terminal comprising an NB-IOT access module, a device management module and a data service module which are connected in turn, a wireless connection with an external device requesting to access an NB-IOT network; data service module in response to determining that the NB-IOT access module of the NB-IOT based device group access terminal has received a command issued from the NB-IOT network to the external device, interpreting the command into a communication command protocol supported by the external device and issuing the interpreted command to the external device corresponding to the command; said data service module in response to determining that the device management module of NB-IOT based device group access terminal has received information uploaded by the external device with the established wireless connection, interpreting the information into a communication command protocol supported by the NB-IOT network and uploading the interpreted information to the NB-IOT network; wherein establishing, by the device management module of the NB-IOT based device group access terminal, the wireless connection with the external device requesting to access the NB-IOT network comprises: in response to determining that the NB-IOT based device group access terminal has received a request initiated by the external device to access the NB-IOT network, said device management module connecting to the external device, allocating an independent NB-IOT access identifier, ID, to the connected external device, and the NB-IOT access module causing the external device to access the NB-IOT network through the NB-IOT access ID of the external device. establishing, by a device management module of an NB-IOT based device group access terminal comprising an NB-IOT access module, a device management module and a data service module which are connected in turn, a wireless connection with an external device requesting to access an NB-IOT network; data service module in response to determining that the NB-IOT access module of the NB-IOT based device group access terminal has received a command issued from the NB-IOT network to the external device, interpreting the command into a communication command protocol supported by the external device and issuing the interpreted command to the external device corresponding to the command; said data service module in response to determining that the device management module of NB-IOT based device group access terminal has received information uploaded by the external device with the established wireless connection, interpreting the information into a communication command protocol supported by the NB-IOT network and uploading the interpreted information to the NB-IOT network; wherein establishing, by the device management module of the NB-IOT based device group access terminal, the wireless connection with the external device requesting to access the NB-IOT network comprises: in response to determining that the NB-IOT based device group access terminal has received a request initiated by the external device to access the NB-IOT network, said device management module connecting to the external device, allocating an independent NB-IOT access identifier, ID, to the connected external device, and the NB-IOT access module causing the external device to access the NB-IOT network through the NB-IOT access ID of the external device.