Radio frame transmitting method and device

Disclosed is a radio frame transmitting method, for transmitting a null data packet NDP to a receiving end. The null data packet NDP comprises at least two VHT long training fields VHT-LTFs. The maximum number of the VHT long training fields VHT-LTFs is determined by the number of VHT long training fields VHT-LTFs that at least one receiving end can support. Also disclosed is a radio frame transmitting device. Through the solution of the present invention, the number of VHT-LTFs in the null data packet can be more reasonable and can better reflect the characteristics of the receiving end.