The invention discloses a method and a device for acquiring transmission data, which are used for solving the problem of the prior art that the accuracy of acquiring data of underground parameters is poor. The method comprises the following steps: carrying out relevant operation on a first signal received by a receiving terminal and a second signal generated locally through the receiving terminal, wherein the first signal consists of an identification signal and data, and the second signal consists of a plurality of identification signals; determining the position of the identification signalin the first signal according to the result of the relevant operation; determining the time of receiving the first signal according to the position of the identification signal; and acquiring the data in the first signal according to the time of receiving the first signal. The scheme provided by the invention can effectively improve the accuracy of acquiring the data transmitted by a sending terminal, thereby being able to accurately acquire the data of the underground parameters.