Gray code (Gray code) is one kind of quasi-weight code, set The lowest point of the gray code is n = 1, The absolute value of the gray code weight is (2^n)-1, and its notation alternates positive and negative from left to right. Typical Gray code is one kind of single-step self-complementing code with reflection characteristics and cyclic characteristics. Its cyclic and single-step characteristics eliminate the possibility of major errors when random number is taken. Gray code is a reliable coding method, which is one kind of error minimization coding method.