Data transmission method and related device

The present application provides a data transmission method and a related device. A controller of an unmanned aerial vehicle receives target data transmitted by a transmitting end, wherein the transmitting end is a ground control device or an onboard apparatus of the unmanned aerial vehicle, the onboard apparatus is connected to the unmanned aerial vehicle by means of a universal interface of the unmanned aerial vehicle, and the universal interface is used for connecting different types of onboard apparatuses. The controller forwards the target data to a receiving end which is a ground control device or an onboard apparatus and is different from the transmitting end. The method and related device can achieve data communication between an onboard apparatus externally connected to an unmanned aerial vehicle and a ground control device for the unmanned aerial vehicle, so as to more reliably control the unmanned aerial vehicle.