the present invention discloses a method for configuring and indicating physical random access channel parameter in a time division duplex system , suitable for the long term evolution , system , including : the same prach configuration set is stored in a base station and a terminal respectively ; when performing a prach configuration , the terminal inquires the prach configuration set according to configuration information to obtain a configuration parameter , and / or the terminal computes to obtain the configuration parameter according to a system parameter . set by using the method provided by the present invention , the prach configuration set can provide enough density types for various prach formats in order to meet the requirements of different system loads , and meanwhile can provide enough version types for each combination of format and density , decrease the processing load of the base station , and reduce the inter - cell interference .