The present invention discloses a method for de-spreading quadrature pseudorandom noise, which including: inputting data sequences I′ and Q′, and inputting pseudorandom noise sequences PNI and PNQ, on which quadrature pseudorandom noise de-spreading operation will be performed; in each timeslot, extracting continuously 2048 codeword from each pseudorandom noise sequence PNI and each pseudorandom noise sequence PNQ respectively, performing time-division de-multiplexing operation on the 2048 codeword respectively, and obtaining pseudorandom noise sequences PNI′ and PNQ′ both with a length of 1600 codeword; performing quadrature pseudorandom noise de-spreading operation on the pseudorandom noise sequences PNI′ and PNQ′ and the data sequences I′ and Q′ with a length of 1600 codeword input in the timeslot, and then outputting data sequences I and Q. The invention operates the input sequences to be performed with quadrature PN de-spreading. Thereby, system transmission requirement is satisfied, and complexity of transmitting end is relatively lowered.