Two improved blind equalization algorithms based on constellation chart are put forward,aiming to solve the high mean square error in MMA-Assisted Modulus Algorithm.Firstly,the 16QAM constellation chart information is used to increase the signal point number of cost function of MMA-Assisted Modulus Algorithm,thus get the improved blind equalization algorithm,which reduces the steady-state mean square error and slightly improves the convergence speed of equalizer.Secondly,integrate the improved blind equalization algorithm and decision direction algorithm,adjust the proportion of the two algorithm according to the mean square error,and get a hybrid algorithm,which can further reduce the steady-state mean square error.The acoustic channel simulation results show that the two improved blind equalization algorithms have smaller mean square error,and are suitable for applications with high accuracy requirement.