In this paper,we propose a method to generate millimeter-wave (mm-w ave) vortex and a communication scheme for W-band mm-wave orbital angular momentum (OAM) multi- dimension modulation and demodulation based on radio-over-fiber (ROF) technology.We empl oy ROF technology in the light field to generate W-band optical mm-wave by frequency multiplicat ion,and we regulate phase and amplitude of the optical mm-wave in the integrated optical modulator.By adj usting the phase shift of mm-wave radiated by circular array antennas,we can achieve the generation and state switching of mm-wave vortex.Meanwhile,we also design a 64-order three-dimensional modu lation format consisting of OAM,phase and amplitude.And through the simulation,the modulation and demo dulation of 75Gbit/s high order joint modulation signal are realized successfully.The results show th at the OAM as a new physical dimension can not only be used to improve the transmission capacity density by m ultiplexing,but also be used to improve the transmission capacity as a modulatio n means.And it has important potential application value in improving wireless spectrum efficiency and secure communica tion.