A first terminal for implementing intelligent communication, wherein there is a voice channel, established by using a circuit switched domain, between the first terminal and a second terminal, and the first terminal comprises: a generation unit, configured to generate a feature code of the first terminal, and generate, based on the feature code, a voice packet, wherein the voice packet comprises the feature code; a first sending unit, configured to send the voice packet to the second terminal by using the voice channel; a second sending unit, configured to send the feature code of the first terminal to a server, for security authentication, wherein the security authentication is completed by the server based on the feature code of the first terminal and a received feature code of the second terminal; and a processing unit, configured to establish a data link channel between the first terminal and the second terminal after the security authentication succeeds; wherein when both the data link channel and the voice channel are established between the first terminal and the second terminal, and the first terminal sends service data to the second terminal, the first terminal further comprises: a determining unit, configured to determine whether the service data is greater than a preset threshold, wherein: if the determining unit determines that the service data is greater than the preset threshold, the second sending unit sends the service data to the second terminal by using the data link channel between the first terminal and the second terminal; or if the determining unit determines that the service data is less than or equal to the preset threshold, the service data is encoded according to an encoding rule to obtain a voice packet transmittable on the voice channel, and the first sending unit sends the voice packet to the second terminal by using the voice channel. a generation unit, configured to generate a feature code of the first terminal, and generate, based on the feature code, a voice packet, wherein the voice packet comprises the feature code; a first sending unit, configured to send the voice packet to the second terminal by using the voice channel; a second sending unit, configured to send the feature code of the first terminal to a server, for security authentication, wherein the security authentication is completed by the server based on the feature code of the first terminal and a received feature code of the second terminal; and a processing unit, configured to establish a data link channel between the first terminal and the second terminal after the security authentication succeeds; wherein when both the data link channel and the voice channel are established between the first terminal and the second terminal, and the first terminal sends service data to the second terminal, the first terminal further comprises: a determining unit, configured to determine whether the service data is greater than a preset threshold, wherein: if the determining unit determines that the service data is greater than the preset threshold, the second sending unit sends the service data to the second terminal by using the data link channel between the first terminal and the second terminal; or if the determining unit determines that the service data is less than or equal to the preset threshold, the service data is encoded according to an encoding rule to obtain a voice packet transmittable on the voice channel, and the first sending unit sends the voice packet to the second terminal by using the voice channel.