A transmission opportunity control method in a wireless local area network, WLAN, performed by an access point, the method comprising the steps of: • determining a handover threshold based on a network status, and sending the handover threshold to a non-access point station, STA, wherein the handover threshold is a contention time that is provided by the access point for the STA and that is used to contend for a channel; • sending (S 201) a first frame to the STA, wherein the first frame carries a TXOP handover enforcement, THE, indication field, ∘ wherein a value of the THE indication field is a first value or a second value, the first value is used to instruct the STA that has accessed the channel to hand over a held TXOP to the access point, and the second value is used to instruct the STA that has accessed the channel to hand over the held TXOP to the access point when a handover condition is satisfied, wherein the handover condition comprises: ▪ a time used by the STA to obtain the channel through contention is greater than the handover threshold; • receiving (S 204, S 206) a second frame from the STA when: ∘ the value of the THE indication field is the first value, or ∘ the value of the THE indication field is the second value and the handover condition is satisfied, wherein the information of the second frame is used to instruct to hand over the TXOP held by the STA from the STA to the access point. • determining a handover threshold based on a network status, and sending the handover threshold to a non-access point station, STA, wherein the handover threshold is a contention time that is provided by the access point for the STA and that is used to contend for a channel; • sending (S 201) a first frame to the STA, wherein the first frame carries a TXOP handover enforcement, THE, indication field, ∘ wherein a value of the THE indication field is a first value or a second value, the first value is used to instruct the STA that has accessed the channel to hand over a held TXOP to the access point, and the second value is used to instruct the STA that has accessed the channel to hand over the held TXOP to the access point when a handover condition is satisfied, wherein the handover condition comprises: ▪ a time used by the STA to obtain the channel through contention is greater than the handover threshold; ∘ wherein a value of the THE indication field is a first value or a second value, the first value is used to instruct the STA that has accessed the channel to hand over a held TXOP to the access point, and the second value is used to instruct the STA that has accessed the channel to hand over the held TXOP to the access point when a handover condition is satisfied, wherein the handover condition comprises: ▪ a time used by the STA to obtain the channel through contention is greater than the handover threshold; ▪ a time used by the STA to obtain the channel through contention is greater than the handover threshold; • receiving (S 204, S 206) a second frame from the STA when: ∘ the value of the THE indication field is the first value, or ∘ the value of the THE indication field is the second value and the handover condition is satisfied, wherein the information of the second frame is used to instruct to hand over the TXOP held by the STA from the STA to the access point. ∘ the value of the THE indication field is the first value, or ∘ the value of the THE indication field is the second value and the handover condition is satisfied, wherein the information of the second frame is used to instruct to hand over the TXOP held by the STA from the STA to the access point. <EOS>