A method for mapping physical random access channel (PRACHs) is provided in the present invention, wherein W PRACHs have the same time domain location and the serial number of each PRACH is w=0, 1, 2, . . . , W−1. The method includes: mapping the PRACHs with the odd w numbers from high frequency to low frequency, or from low frequency to high frequency in a usable frequency band, mapping the PRACHs with the even w numbers from low frequency to high frequency, or from high frequency to low frequency in the usable frequency band. One PRACH occupies 6 continuous resource blocks in the frequency domain, and the frequency bands occupied by the two adjacent PRACHs in the frequency domain do not overlap, furthermore the same mapping process is used for each version number r. The PRACHs which need to be processed by the same station could be distributed evenly in the time domain, and at the same time the inter-cell interference of the second type PRACH could be reduced to the greatest extent through the present invention.