Embodiments of this application provide a preamble transmission method, an apparatus, and a system. The method includes: A terminal device obtains first information. The first information includes at least one of the following: historical timing advance TA information, geographical location information, or power information of the terminal device. The terminal device determines one group of preambles from KG groups of preambles based on the first information. KG is an integer greater than 1, a total quantity of preambles in the KG groups of preambles is positively correlated with a quantity of preamble cyclic shifts, and the quantity of preamble cyclic shifts is positively correlated with the quantity KG of groups of preambles. The terminal device sends a first preamble in the one group of preambles to a network device.