The transmission of high-dimensional quantum information can be achieved by the eigenstates of the beam’s orbital angular momentum, which can be used for information encoding to increase the data storage density. The phase encoding method of the eight quadrant staircase structure which depends on the phase rotation angle of the incident light beam to control the phase delay is presented, thus realizing the code phase information. The distribution of the spiral spectrum that the incident beam passes through different quadrant staircase structures, and detects the spiral spectrum by the array power detector corresponding to the particular coding quadrant staircase structure, distinguishes different data states and finally achieves the decode of the phase information. Each memory cell can theoretically encode 24 bits data, which is three times the four quadrant staircase structure.