A wireless fidelity, Wi-Fi, monitoring method, the method comprising: obtaining, by each AP in M APs when the each AP sends N data packets within a latest preset period, a time Tbuffer of putting each data packet in the N data packets into a buffer queue and a time Tsend of sending the each data packet to a wireless channel, wherein M is an integer larger than or equal to 2, and N is an integer larger than or equal to 1; determining, by the each AP, an average data packet sending delay of the each AP within the latest preset period according to time Tbuffer and time Tsend of each data packet in the N data packets, wherein the each AP adopts a following formula to calculate the average data packet sending delay of the each AP within the latest preset period: η = 1 N ∑ i = 1 N Tsend i − Tbuffer i, wherein η represents the average data packet sending delay of the each AP, which serves as a current calculating object, within the latest preset period, and Tbuffer (i) and Tsend (i) respectively represent a time Tbuffer (i) of putting an i th data packet in the N data packets into the buffer queue and a time Tsend (i) of sending the i th data packet to the wireless channel; carrying, by the each AP, the average data packet sending delay of the each AP within the latest preset period in a beacon frame periodically sent by the each AP correspondingly; obtaining, by a STA, when monitoring a beacon frame of each AP in a plurality of APs in a peripheral area, the average data packet sending delay of a corresponding AP within the latest preset period from various beacon frames monitored; and determining, by the STA, whether average data packet sending delays corresponding to the M APs satisfy a first preset judgment rule, determining, by the STA, a target AP from the M APs, whose average data packet sending delay satisfies the first judgment rule, and associating with the target AP. obtaining, by each AP in M APs when the each AP sends N data packets within a latest preset period, a time Tbuffer of putting each data packet in the N data packets into a buffer queue and a time Tsend of sending the each data packet to a wireless channel, wherein M is an integer larger than or equal to 2, and N is an integer larger than or equal to 1; determining, by the each AP, an average data packet sending delay of the each AP within the latest preset period according to time Tbuffer and time Tsend of each data packet in the N data packets, wherein the each AP adopts a following formula to calculate the average data packet sending delay of the each AP within the latest preset period: η = 1 N ∑ i = 1 N Tsend i − Tbuffer i, wherein η represents the average data packet sending delay of the each AP, which serves as a current calculating object, within the latest preset period, and Tbuffer (i) and Tsend (i) respectively represent a time Tbuffer (i) of putting an i th data packet in the N data packets into the buffer queue and a time Tsend (i) of sending the i th data packet to the wireless channel; carrying, by the each AP, the average data packet sending delay of the each AP within the latest preset period in a beacon frame periodically sent by the each AP correspondingly; obtaining, by a STA, when monitoring a beacon frame of each AP in a plurality of APs in a peripheral area, the average data packet sending delay of a corresponding AP within the latest preset period from various beacon frames monitored; and determining, by the STA, whether average data packet sending delays corresponding to the M APs satisfy a first preset judgment rule, determining, by the STA, a target AP from the M APs, whose average data packet sending delay satisfies the first judgment rule, and associating with the target AP. wherein η represents the average data packet sending delay of the each AP, which serves as a current calculating object, within the latest preset period, and Tbuffer (i) and Tsend (i) respectively represent a time Tbuffer (i) of putting an i th data packet in the N data packets into the buffer queue and a time Tsend (i) of sending the i th data packet to the wireless channel; carrying, by the each AP, the average data packet sending delay of the each AP within the latest preset period in a beacon frame periodically sent by the each AP correspondingly; obtaining, by a STA, when monitoring a beacon frame of each AP in a plurality of APs in a peripheral area, the average data packet sending delay of a corresponding AP within the latest preset period from various beacon frames monitored; and determining, by the STA, whether average data packet sending delays corresponding to the M APs satisfy a first preset judgment rule, determining, by the STA, a target AP from the M APs, whose average data packet sending delay satisfies the first judgment rule, and associating with the target AP.