The embodiment of the invention relates to the communication field, which provides a distance measurement method, a wireless access system and a base station in a communication system. A priority classification to a CDMA codeword is achieved in advance; wherein, at least one CDMA codeword is appointed as a competitive code with high priority; therefore, when a base station receives the CDMA codeword which is sent by a terminal and discovered as the competitive code, the distance measurement success is indicated, and a physical resource is distributed to the CDMA codeword and indicated to the terminal through a UL-MAP message, thus reducing the access relay of the terminal in the initial Ranging process of network access, improving the execution efficiency of the Ranging process, further shortening the time relay of the whole network access.