Proposed are a method and device for receiving an EHT PPDU on the basis of a tone plan in a wireless LAN system. Specifically, a reception STA receives the EHT PPDU from a transmission STA through a 320 MHz band. The reception STA decodes the EHT PPDU. The EHT PPDU includes a control field and a data field. The control field includes information about a pilot tone. The information about the pilot tone includes allocation information indicating that a first pilot tone for the 320 MHz band is configured by repeating a second pilot tone for an 80 MHz band defined in an 802.11ax wireless LAN system. The first pilot tone is received in a data field on the basis of the allocation information.