The present invention discloses a wireless transmission rate adjustment method for adjusting the wireless transmission rate of a wireless transmission device. The method comprises: having the wireless transmission device enter a try state from a normal state; under the try state, transmitting a plurality of test packets according to a first modulation and coding scheme (MCS) and determining whether the transmission is successful in accordance with a predetermined condition; if the transmission is successful with the first MCS, returning to the normal state and transmitting data with the first MCS; if the transmission is unsuccessful with the first MCS, staying in the try state and transmitting a plurality of test packets according to a second MCS, and then determining whether the transmission is successful in accordance with the predetermined condition; if the transmission is successful with the second MCS, returning to the normal state and transmitting data with the second MCS; and if the transmission is failed with the second MCS, returning to the normal state and transmitting data at an original transmission rate or with the first MCS.