Sending method and device of random access signals in LTE system TDD mode

The present invention provides a method for transmitting a random access signal in a TDD mode of a LTE system and a device thereof. The method comprises the following procedures: obtaining a maximum allowed value Tud-max of the switching time from ascending to descending in the TDD mode of the LTE system; determining whether the Tud-max is larger than a first predetermined value; if the Tud-max is not larger than the first predetermined value, setting that a fourth structure of RACH is transmitted at an advanced second predetermined value of the UpPTS end position; and if the Tud-max is larger than the first predetermined value, setting that the fourth structure is transmitted at an advanced third predetermined value of the UpPTS end position. The invention effectively increases the coverage of the random access channel and the working efficiency of the TDD system.