The invention discloses an equivalent subcarrier allocation system and method of multi-user multi-tone code division multiple access MT-CDMA. The system and the method comprises the steps of obtaining a gain value of each user on each equivalent subcarrier in an MT-CDMA system according to a channel gain value of each user on each subcarrier; evaluating that how many equivalent subcarriers does each user need to select for transmission according to a user data speed threshold value, wherein the subcarriers in the sub-blocks are ensured to have similar transmission characteristics by use of an evenly-spaced subcarrier block diversity mode; carrying out equivalent subcarrier allocation according to an irrigation principle by taking each subcarrier sub-block as an equivalent subcarrier. The system and the method have the advantages that the characteristic that the speed difference of the users are relatively high is taken into consideration, different speed demands of the multi-user MT-CDMA system can be satisfied, the system and the method are compatible with an existing self-adaptive resource allocation system of multi-user MT-CDMA, and the existing system can be modified conveniently.