A method for correcting Gamma characteristics of a video bit-stream in a video communication, characterized by comprising: sending, by a video bit-stream transmitting terminal, a first video bit-stream to a multipoint control unit, wherein the first video bit-stream comprises video data generated according to a video image of the transmitting terminal and Gamma characteristic parameter information of the transmitting terminal; receiving, by the multipoint control unit, the first video bit-stream, restoring the video image according to the video data, and performing a one-time Gamma correction for the video image according to the Gamma characteristic parameter information of the transmitting terminal; and generating video data of the video image that is one-time corrected, putting the video data generated into a second video bit-stream, and sending the second video bit-stream to a receiving terminal; wherein the Gamma characteristic parameter information of the transmitting terminal comprises: the Gamma characteristic parameters of each Gamma characteristic element passed by the video image in the transmitting terminal during processes of collecting and processing of the video image as well as forming the video bit-stream, and a cascading sequence of each Gamma characteristic element; or equivalent Gamma characteristic parameters determined by the transmitting terminal according to all the Gamma characteristic elements that are passed; the Gamma characteristic parameters of each Gamma element or the equivalent Gamma characteristic parameters comprise a set of output luminance signal values corresponding to each level of input luminance signal values of preconfigured levels. sending, by a video bit-stream transmitting terminal, a first video bit-stream to a multipoint control unit, wherein the first video bit-stream comprises video data generated according to a video image of the transmitting terminal and Gamma characteristic parameter information of the transmitting terminal; receiving, by the multipoint control unit, the first video bit-stream, restoring the video image according to the video data, and performing a one-time Gamma correction for the video image according to the Gamma characteristic parameter information of the transmitting terminal; and generating video data of the video image that is one-time corrected, putting the video data generated into a second video bit-stream, and sending the second video bit-stream to a receiving terminal; wherein the Gamma characteristic parameter information of the transmitting terminal comprises: the Gamma characteristic parameters of each Gamma characteristic element passed by the video image in the transmitting terminal during processes of collecting and processing of the video image as well as forming the video bit-stream, and a cascading sequence of each Gamma characteristic element; or equivalent Gamma characteristic parameters determined by the transmitting terminal according to all the Gamma characteristic elements that are passed; the Gamma characteristic parameters of each Gamma element or the equivalent Gamma characteristic parameters comprise a set of output luminance signal values corresponding to each level of input luminance signal values of preconfigured levels. the Gamma characteristic parameters of each Gamma characteristic element passed by the video image in the transmitting terminal during processes of collecting and processing of the video image as well as forming the video bit-stream, and a cascading sequence of each Gamma characteristic element; or equivalent Gamma characteristic parameters determined by the transmitting terminal according to all the Gamma characteristic elements that are passed; the Gamma characteristic parameters of each Gamma element or the equivalent Gamma characteristic parameters comprise a set of output luminance signal values corresponding to each level of input luminance signal values of preconfigured levels.