The present invention relates to the technical field of wireless communications. Disclosed are a method, system and device for determining a transmission link type, to solve the receiving/transmitting duplexing problem in the prior art of a D2D link receiving terminal on a D2D link and an N2D link. The method comprises: a D2D receiving terminal reports to a network side device a first resource usage request on an N2D link, such that the network side device, after receiving the first resource usage request, determines the transmission link type of the D2D receiving terminal over a subframe n; and according to the type of the subframe n or the link type indication information received from the network side device, the D2D receiving terminal determines the transmission link type over the subframe n, the subframe n being a D2D subframe. An embodiment of the present invention improves system resource utilization and system performance.