A pre-processing blind multiuser detection algorithms based on the least squares constant modulus (PLSCMA) using antenna array is proposed in this paper. It first uses the signals received from every antenna to correlate with the conjugation of the DoA vector of the expected user, and then applies the pre-processed signals to the LSCMA. We simulate and compare the proposed algorithm with the conventional LSCMA Simulation results show that the proposed algorithm is superior to LSCMA.