A WLAN system resource indication method, comprising: generating, by an access point, a trigger frame that carries resource indication information; and sending, by the access point, the trigger frame, wherein the resource indication information comprises multiple pieces of sub resource indication information, and each piece of the sub resource indication information comprises an identifier of one station, and frequency domain resource allocation information of the one station, characterized in that the frequency domain resource allocation information comprises one index, the index indicating a size and a location of one frequency domain resource unit, RU, in a bandwidth of the WLAN system, for different bandwidths of the WLAN system, the index is one of multiple indexes in the following: indexes "0-36", each of which indicating a RU of 26 tones allocated to the one station; indexes "37-52", each of which indicating a RU of 52 tones allocated to the one station; indexes "53-60", each of which indicating a RU of 106 tones allocated to the one station; indexes "61-64", each of which indicating a RU of 242 tones allocated to the one station; indexes "65-66", each of which indicating a RU of 484 tones allocated to the one station; index "67", indicating a RU of 996 tones allocated to the one station; indexes "68-127", each of which being reserved. generating, by an access point, a trigger frame that carries resource indication information; and sending, by the access point, the trigger frame, wherein the resource indication information comprises multiple pieces of sub resource indication information, and each piece of the sub resource indication information comprises an identifier of one station, and frequency domain resource allocation information of the one station, characterized in that the frequency domain resource allocation information comprises one index, the index indicating a size and a location of one frequency domain resource unit, RU, in a bandwidth of the WLAN system, for different bandwidths of the WLAN system, the index is one of multiple indexes in the following: indexes "0-36", each of which indicating a RU of 26 tones allocated to the one station; indexes "37-52", each of which indicating a RU of 52 tones allocated to the one station; indexes "53-60", each of which indicating a RU of 106 tones allocated to the one station; indexes "61-64", each of which indicating a RU of 242 tones allocated to the one station; indexes "65-66", each of which indicating a RU of 484 tones allocated to the one station; index "67", indicating a RU of 996 tones allocated to the one station; indexes "68-127", each of which being reserved. indexes "0-36", each of which indicating a RU of 26 tones allocated to the one station; indexes "37-52", each of which indicating a RU of 52 tones allocated to the one station; indexes "53-60", each of which indicating a RU of 106 tones allocated to the one station; indexes "61-64", each of which indicating a RU of 242 tones allocated to the one station; indexes "65-66", each of which indicating a RU of 484 tones allocated to the one station; index "67", indicating a RU of 996 tones allocated to the one station; indexes "68-127", each of which being reserved.