A method for sending information, which is applied in a control device, said method comprising the steps of: establishing connections with smart devices through a wireless network, wherein said step of establishing comprises the step of storing identifications of the smart devices and the corresponding states of said smart devices as being in a user operation state or in a user disabling state; and when identifying a device which is in the user operation state, acquiring information about the device which is in the user operation state; and returning, the information about the device in the user operation state to a smart device, from which a request for acquiring a device which is in the user operation state was previously received, said method being characterized in that: said step of establishing connections with smart devices further comprises the steps of: when firstly establishing a connection with a smart device, acquiring an image of the smart device; and storing the image of the smart device as corresponding to an identification of the smart device; and in that said step of acquiring information about the device which is in the user operation state comprises the steps of: when no information about the device which is in the user operation state is retrieved, determining a current location of a user with an indoor positioning technique; acquiring an image of a smart device which is in a set range about the user; and matching the acquired image with the stored image of the smart device to obtain a similarity, if the similarity is larger than a set threshold, determining the smart device corresponding to the image as the smart device which is in the user operation sate. establishing connections with smart devices through a wireless network, wherein said step of establishing comprises the step of storing identifications of the smart devices and the corresponding states of said smart devices as being in a user operation state or in a user disabling state; and when identifying a device which is in the user operation state, acquiring information about the device which is in the user operation state; and returning, the information about the device in the user operation state to a smart device, from which a request for acquiring a device which is in the user operation state was previously received, said method being characterized in that: said step of establishing connections with smart devices further comprises the steps of: when firstly establishing a connection with a smart device, acquiring an image of the smart device; and storing the image of the smart device as corresponding to an identification of the smart device; and in that said step of acquiring information about the device which is in the user operation state comprises the steps of: when no information about the device which is in the user operation state is retrieved, determining a current location of a user with an indoor positioning technique; acquiring an image of a smart device which is in a set range about the user; and matching the acquired image with the stored image of the smart device to obtain a similarity, if the similarity is larger than a set threshold, determining the smart device corresponding to the image as the smart device which is in the user operation sate. when firstly establishing a connection with a smart device, acquiring an image of the smart device; and storing the image of the smart device as corresponding to an identification of the smart device; and in that said step of acquiring information about the device which is in the user operation state comprises the steps of: when no information about the device which is in the user operation state is retrieved, determining a current location of a user with an indoor positioning technique; acquiring an image of a smart device which is in a set range about the user; and matching the acquired image with the stored image of the smart device to obtain a similarity, if the similarity is larger than a set threshold, determining the smart device corresponding to the image as the smart device which is in the user operation sate. when no information about the device which is in the user operation state is retrieved, determining a current location of a user with an indoor positioning technique; acquiring an image of a smart device which is in a set range about the user; and matching the acquired image with the stored image of the smart device to obtain a similarity, if the similarity is larger than a set threshold, determining the smart device corresponding to the image as the smart device which is in the user operation sate.