Signal transmission method and related device

The embodiment of the invention discloses a signal transmission method and a related device. In the method, a modulo test sending terminal determines a current modulo test scene demand, the modulo test sending terminal sends a first downlink public signal according to the current modulo test scene demand, and a reserved field in a main information block in the first downlink public signal indicates whether the first downlink public signal comprises system information of a service cell. Therefore, whether the system information of the service cell is sent or not can be determined according to the requirement of the modular measurement scene, so that the data volume of the sent first downlink public signal can be reduced in the modular measurement scene without the system information of the service cell, the power consumption of the modular measurement sending terminal can be reduced, and the endurance time of the modular measurement sending terminal in network regulation and network optimization can be prolong