In a signal transmission method, a user equipment receives a first signal from a wireless network device; and the user equipment determines spatial information of a to-be-transmitted second signal based on the first signal, and transmits the to-be-transmitted second signal by using the spatial information. An uplink transmit beam is determined by using related information of a downlink receive beam, so that the UE can efficiently determine spatial information of an uplink signal to be transmitted by the UE.