1. A real-time voice transmission method, comprising: at a mobile terminal having one or more processors and memory storing program modules to be executed by the one or more processors: starting collecting voice signal in response to a first user instruction; while collecting the voice signal: encoding and compressing the collected voice signal into voice data; identifying the voice data as a voice data segment and adding a transmission sequence identifier to the voice data segment when the length of voice data reaches a preset data length, wherein the transmission sequence identifier indicates a processing order of the voice data segment; generating and displaying a first visual indicator after sending the voice data segment to a voice server; stopping collecting the voice signal in response to a second user instruction; identifying remaining voice data as a last voice data segment and adding a last transmission sequence identifier to the last voice data segment; and generating and displaying a second visual indicator after sending the last voice data segment to the voice server.