A method of transmitting intelligent information and video data on a Serial Digital Interface SDI between a SDI sending terminal and a SDI receiving terminal, wherein the intelligent information is generated by a device which generates the video data, comprising: - determining, by the Serial Digital Interface SDI sending terminal, whether there is intelligent information satisfying a transmission condition when one frame of video data x is to be transmitted on the Serial Digital Interface; wherein the intelligent information is information related to another frame of video data which was transmitted on the serial digital interface, and the transmission condition is satisfied when both the intelligent information is not yet transmitted and the transmission on the Serial Digital Interface of the frame of video data corresponding to the intelligent information is finished; wherein if there is intelligent information satisfying the transmission condition, adding, by the SDI sending terminal, an item y of the intelligent information into a preset position of the frame of video data x; and - transmitting, by the SDI sending terminal, the frame of video data x having the item of intelligent information y on the Serial Digital Interface; wherein the preset position of the frame of video data x consists of the first two rows of valid data in the frame of video data x, the last two rows of valid data in the frame of video data x or a frame blanking row of the frame of video data x; wherein adding the item of intelligent information y into the preset position of the frame of video data x comprises: - encapsulating the item of intelligent information y into a Payload of an intelligent information element, the intelligent information element comprising also a Header, - adding the intelligent information element into the preset position of the frame of video data x; wherein the Header comprises a TIME_STAMP_V field, a TIME_STAMP_I field and a V field; the TIME_STAMP_V field carrying a time stamp of the frame of video data x, the TIME_STAMP_I field carrying a time stamp of the frame of video data corresponding to the item of intelligent information y, the V field carrying an identifier indicating whether contents in the Payload is valid; and - setting, when the item of intelligent information y is encapsulated into the payload, the identifier carried in the V field to indicate that the content in the Payload is valid; the method further comprising: - determining, after receiving the frame of video data x by the SDI receiving terminal, whether the content in the Payload is valid according to the identifier carried by the V field of the video data x; - extracting, by the SDI receiving terminal, the item of intelligent information y from the Payload if the contents in the Payload is valid; - searching, by the SDI receiving terminal, each frame of received video data except the video data x for a frame of video data having a time stamp carried in a TIME_STAMP_V field of the frame of video data being identical with the time stamp carried by the TIME_STAMP_I field of the video data x; and - matching, by the SDI receiving terminal, the frame of video data with the item of intelligent information y, if the frame of video data is found. - determining, by the Serial Digital Interface SDI sending terminal, whether there is intelligent information satisfying a transmission condition when one frame of video data x is to be transmitted on the Serial Digital Interface; - transmitting, by the SDI sending terminal, the frame of video data x having the item of intelligent information y on the Serial Digital Interface; - encapsulating the item of intelligent information y into a Payload of an intelligent information element, the intelligent information element comprising also a Header, - adding the intelligent information element into the preset position of the frame of video data x; - setting, when the item of intelligent information y is encapsulated into the payload, the identifier carried in the V field to indicate that the content in the Payload is valid; - determining, after receiving the frame of video data x by the SDI receiving terminal, whether the content in the Payload is valid according to the identifier carried by the V field of the video data x; - extracting, by the SDI receiving terminal, the item of intelligent information y from the Payload if the contents in the Payload is valid; - searching, by the SDI receiving terminal, each frame of received video data except the video data x for a frame of video data having a time stamp carried in a TIME_STAMP_V field of the frame of video data being identical with the time stamp carried by the TIME_STAMP_I field of the video data x; and - matching, by the SDI receiving terminal, the frame of video data with the item of intelligent information y, if the frame of video data is found.