The present invention discloses a data transmission method, user equipment, and a network device. A D2D communications system configures a logical channel used by different types of D2D data and configures a resource selection parameter for user equipment. In this way, the user equipment is capable of selecting a communication resource by itself according to the resource selection parameter and D2D data to be transmitted by the user equipment, and allocating the resource to the to-be-transmitted D2D data, improving system reliability.