A method for establishing a Bluetooth Low Energy, BLE, Isochronous channel, ISOC, comprising: before starting a Bluetooth low energy service using the BLE ISOC for data transmission, negotiating, by a first communications apparatus, with a second communications apparatus to determine a first parameter to be used for transmitting Bluetooth data of a first mode, wherein the first parameter is used for establishing a data channel between the first communications apparatus and the second communications apparatus, and the data channel is used to transmit Bluetooth data of the first mode, wherein the first mode is any one of the following modes: a high-quality music mode, a normal-quality music mode, and a voice mode; and after starting the service in the first mode, sending, by the first communications apparatus, a first message to the second communications apparatus, wherein the first message is used to request the second communications apparatus to establish the data channel based on the first parameter; wherein the negotiating, by a first communications apparatus, with a second communications apparatus to determine a first parameter comprises: sending, by the first communications apparatus, a second message to the second communications apparatus, wherein the second message is used to request to negotiate a parameter used when the Bluetooth data of the first mode is transmitted between the first communications apparatus and the second communications apparatus; and receiving, by the first communications apparatus, a third message sent by the second communications apparatus, wherein the third message is used to determine the first parameter; wherein the second message is a logical link control and adaptation protocol, L2CAP, message. before starting a Bluetooth low energy service using the BLE ISOC for data transmission, negotiating, by a first communications apparatus, with a second communications apparatus to determine a first parameter to be used for transmitting Bluetooth data of a first mode, wherein the first parameter is used for establishing a data channel between the first communications apparatus and the second communications apparatus, and the data channel is used to transmit Bluetooth data of the first mode, wherein the first mode is any one of the following modes: a high-quality music mode, a normal-quality music mode, and a voice mode; and after starting the service in the first mode, sending, by the first communications apparatus, a first message to the second communications apparatus, wherein the first message is used to request the second communications apparatus to establish the data channel based on the first parameter; wherein the negotiating, by a first communications apparatus, with a second communications apparatus to determine a first parameter comprises: sending, by the first communications apparatus, a second message to the second communications apparatus, wherein the second message is used to request to negotiate a parameter used when the Bluetooth data of the first mode is transmitted between the first communications apparatus and the second communications apparatus; and receiving, by the first communications apparatus, a third message sent by the second communications apparatus, wherein the third message is used to determine the first parameter; wherein the second message is a logical link control and adaptation protocol, L2CAP, message. sending, by the first communications apparatus, a second message to the second communications apparatus, wherein the second message is used to request to negotiate a parameter used when the Bluetooth data of the first mode is transmitted between the first communications apparatus and the second communications apparatus; and receiving, by the first communications apparatus, a third message sent by the second communications apparatus, wherein the third message is used to determine the first parameter; wherein the second message is a logical link control and adaptation protocol, L2CAP, message.