1. A method for implementing de-scrambling and de-spreading, comprising: performing an operation of complex multiplication on baseband data and corresponding de-scrambling and de-spreading codes by adopting data transformation and addition, and storing data obtained by the complex multiplication into a vector register file; reading from the vector register file a row of data obtained by the complex multiplication, accumulating every two adjacent pieces of data in the row of data to obtain a half row of data, and storing the obtained data back into the vector register file; continuing reading a previous accumulation result from the vector register file or a previous accumulation result reserved in a result register of a vector computing unit, accumulating every two adjacent pieces of data in the previous accumulation result to obtain a ¼ row of data, and continuing accumulation to finally obtain one piece of accumulated data; and continuing the accumulation processing on other rows of data to implement accumulation of each row of data obtained by the complex multiplication in the vector register file.