Abstract: In order to realize multiple-access communication of M-ary Position Phase Shift Keying (MPPSK) modulation, a realization method was researched based on time-hopping. The sending signal was modulated on a continuous sine wave, of which the phase jumped in corresponding time slots according to the symbols ready to send and the time-hopping sequence exclusively assigned to one user. The envelope in corresponding time slots was obtained for demodulation according to the transmission delay and the time-hopping sequence after receipt signal passed through the impacting filter. By simulation, the bit error rate (BER) of time-hopping multiple-access MPPSK and that of non-time-hopping MPPSK were compared under the same modulation parameters. The simulation results show that time-hopping modulated MPPSK signals don't lose BER performance when the time-hopping sequences of users are orthogonal, thus the feasibility and effectiveness of this time-hopping multiple-access realization are demonstrated.