A multimedia stream transmission method based on terahertz wireless communication, comprising the following steps of: S1. processing, by a media providing device, a multimedia stream into a data packet suitable for terahertz wireless signal transmission, and sending the data packet from the first terahertz communication interface drive to the first terahertz transceiver, wherein the first terahertz transceiver externally broadcasts the data packet through a terahertz wireless signal; and S2. receiving, by a media receiving device, the terahertz wireless signal broadcast through the second terahertz transceiver, and acquiring the data packet, wherein after the second terahertz transceiver sends the data packet to the second terahertz communication interface drive, the media receiving device processes the data packet into a playable multimedia stream, wherein the step S1 further comprises the step of: S11. decoding, by the media providing device, the multimedia stream through the first multimedia codec library, and packing the multimedia stream into a data packet suitable for terahertz wireless signal transmission through the first terahertz communication protocol after recoding, wherein the step S2 further comprises the steps of: S22. reading, by the second terahertz communication interface drive, the data packet, wherein after the read data packet is unpacked and corrected by the second terahertz communication protocol stack, the read data packet is decoded and translated into a required image frame by the second multimedia codec library; and S23. translating the image frame, after being drawn by a graphics engine and processed by a display drive, into a playable multimedia stream, wherein the method further comprises a handshake stage before the step S1, which comprises the following steps of: R1. searching, by the media receiving device, an available media providing device through the terahertz wireless signal; R2. receiving, by the media receiving device, an available answering instruction sent out by the media providing device; R3. sending out, by the media receiving device, an authentication code verification instruction to the media providing device; and R4. receiving, by the media receiving device, an authentication code answering instruction sent out by the media providing device, and verifying the authentication code, and wherein the media providing device is a smartphone, a laptop computer or a personal digital assistant that broadcasts the multimedia stream to multiple media receiving devices. S1. processing, by a media providing device, a multimedia stream into a data packet suitable for terahertz wireless signal transmission, and sending the data packet from the first terahertz communication interface drive to the first terahertz transceiver, wherein the first terahertz transceiver externally broadcasts the data packet through a terahertz wireless signal; and S2. receiving, by a media receiving device, the terahertz wireless signal broadcast through the second terahertz transceiver, and acquiring the data packet, wherein after the second terahertz transceiver sends the data packet to the second terahertz communication interface drive, the media receiving device processes the data packet into a playable multimedia stream, S22. reading, by the second terahertz communication interface drive, the data packet, wherein after the read data packet is unpacked and corrected by the second terahertz communication protocol stack, the read data packet is decoded and translated into a required image frame by the second multimedia codec library; and S23. translating the image frame, after being drawn by a graphics engine and processed by a display drive, into a playable multimedia stream, R1. searching, by the media receiving device, an available media providing device through the terahertz wireless signal; R2. receiving, by the media receiving device, an available answering instruction sent out by the media providing device; R3. sending out, by the media receiving device, an authentication code verification instruction to the media providing device; and R4. receiving, by the media receiving device, an authentication code answering instruction sent out by the media providing device, and verifying the authentication code, and wherein the media providing device is a smartphone, a laptop computer or a personal digital assistant that broadcasts the multimedia stream to multiple media receiving devices.