A beam refinement method, wherein the method comprises: determining, by a first device, a format of an enhanced Beam Refinement Protocol eBRP packet, wherein the eBRP packet comprises a training field, and the training field is composed of an eBRP beam refinement automatic gain control eBRP-AGC field and an eBRP beam refinement training eBRP-TRN sub-field; and sending, by the first device, the eBRP packet to a second device based on the determined format of the eBRP packet, characterized in that the determining, by a first device, a format of an enhanced Beam Refinement Protocol eBRP packet comprises: when an antenna quantity of the first device is 1 or 2 and an antenna of the first device is a co-polarized antenna, determining, by the first device, that each eBRP-TRN sub-field in the training field is composed of 5×C 2 Gray codes whose lengths are 128×C 1; when an antenna quantity of the first device is 3 or 4 and an antenna of the first device is a co-polarized antenna, determining, by the first device, that each eBRP-TRN sub-field in the training field is in any one of the following formats: 10×C 2 Gray codes whose lengths are 64 XC 1 or 9×C 2 Gray codes whose lengths are 128×C 1; or when an antenna quantity of the first device is 2 or 4 and an antenna of the first device is a cross-polarized antenna, determining, by the first device, that each eBRP-TRN sub-field in the training field is composed of 5×C 2 Gray codes whose lengths are 128×C 1, wherein when C 2 =1, C 1 is determined by a transmission channel quantity of the first device; or when C 2 is determined by a transmission channel quantity of the first device, C 1 =1. determining, by a first device, a format of an enhanced Beam Refinement Protocol eBRP packet, wherein the eBRP packet comprises a training field, and the training field is composed of an eBRP beam refinement automatic gain control eBRP-AGC field and an eBRP beam refinement training eBRP-TRN sub-field; and sending, by the first device, the eBRP packet to a second device based on the determined format of the eBRP packet, characterized in that the determining, by a first device, a format of an enhanced Beam Refinement Protocol eBRP packet comprises: when an antenna quantity of the first device is 1 or 2 and an antenna of the first device is a co-polarized antenna, determining, by the first device, that each eBRP-TRN sub-field in the training field is composed of 5×C 2 Gray codes whose lengths are 128×C 1; when an antenna quantity of the first device is 3 or 4 and an antenna of the first device is a co-polarized antenna, determining, by the first device, that each eBRP-TRN sub-field in the training field is in any one of the following formats: 10×C 2 Gray codes whose lengths are 64 XC 1 or 9×C 2 Gray codes whose lengths are 128×C 1; or when an antenna quantity of the first device is 2 or 4 and an antenna of the first device is a cross-polarized antenna, determining, by the first device, that each eBRP-TRN sub-field in the training field is composed of 5×C 2 Gray codes whose lengths are 128×C 1, wherein when C 2 =1, C 1 is determined by a transmission channel quantity of the first device; or when C 2 is determined by a transmission channel quantity of the first device, C 1 =1. when an antenna quantity of the first device is 1 or 2 and an antenna of the first device is a co-polarized antenna, determining, by the first device, that each eBRP-TRN sub-field in the training field is composed of 5×C 2 Gray codes whose lengths are 128×C 1; when an antenna quantity of the first device is 3 or 4 and an antenna of the first device is a co-polarized antenna, determining, by the first device, that each eBRP-TRN sub-field in the training field is in any one of the following formats: 10×C 2 Gray codes whose lengths are 64 XC 1 or 9×C 2 Gray codes whose lengths are 128×C 1; or when an antenna quantity of the first device is 2 or 4 and an antenna of the first device is a cross-polarized antenna, determining, by the first device, that each eBRP-TRN sub-field in the training field is composed of 5×C 2 Gray codes whose lengths are 128×C 1, wherein when C 2 =1, C 1 is determined by a transmission channel quantity of the first device; or when C 2 is determined by a transmission channel quantity of the first device, C 1 =1.