Implementations of the present disclosure relate to a method for transmitting a random access preamble, and a terminal device. The method comprises: performing the i-th transmission of a random access preamble, i being a positive integer greater than 1; and if the i-th transmission of the random access preamble is performed by the same wave beam as the (i−1)-th transmission, incrementing the value of a power ramping counter of the random access preamble by 1.