A sidelink data indication method applied to a transmitter device, comprising: determining (S 101) indication information, the indication information comprising at least one of a first identifier or a second identifier, wherein the first identifier is used to identify a first logical channel, the second identifier is used to identify a second logical channel, the first logical channel is used to carry original sidelink data, the second logical channel is used to carry duplicated sidelink data, the duplicated sidelink data is obtained by duplicating the original sidelink data; and sending the indication information; characterized by: wherein the indication information further comprises therein a sidelink radio bearer, SLRB, identifier, wherein the SLRB identifier has a matching relationship with the first identifier and the second identifier; wherein the indication information further comprises a third identifier for identifying a duplication data function state of an SLRB corresponding to the SLRB identifier, wherein the duplication data function state comprises one of an activated state or a deactivated state, or wherein the indication information further comprises therein a first mapping relationship, wherein the first mapping relationship comprises an association relationship between the first identifier and a first frequency domain resource, and an association relationship between the second identifier and a second frequency domain resource, the first frequency domain resource is used to transmit the original sidelink data; the second frequency domain resource is used to transmit the duplicated sidelink data. determining (S 101) indication information, the indication information comprising at least one of a first identifier or a second identifier, wherein the first identifier is used to identify a first logical channel, the second identifier is used to identify a second logical channel, the first logical channel is used to carry original sidelink data, the second logical channel is used to carry duplicated sidelink data, the duplicated sidelink data is obtained by duplicating the original sidelink data; and sending the indication information; characterized by: wherein the indication information further comprises therein a sidelink radio bearer, SLRB, identifier, wherein the SLRB identifier has a matching relationship with the first identifier and the second identifier; wherein the indication information further comprises a third identifier for identifying a duplication data function state of an SLRB corresponding to the SLRB identifier, wherein the duplication data function state comprises one of an activated state or a deactivated state, or wherein the indication information further comprises therein a first mapping relationship, wherein the first mapping relationship comprises an association relationship between the first identifier and a first frequency domain resource, and an association relationship between the second identifier and a second frequency domain resource, the first frequency domain resource is used to transmit the original sidelink data; the second frequency domain resource is used to transmit the duplicated sidelink data. wherein the indication information further comprises therein a sidelink radio bearer, SLRB, identifier, wherein the SLRB identifier has a matching relationship with the first identifier and the second identifier; wherein the indication information further comprises a third identifier for identifying a duplication data function state of an SLRB corresponding to the SLRB identifier, wherein the duplication data function state comprises one of an activated state or a deactivated state, or wherein the indication information further comprises therein a first mapping relationship, wherein the first mapping relationship comprises an association relationship between the first identifier and a first frequency domain resource, and an association relationship between the second identifier and a second frequency domain resource, the first frequency domain resource is used to transmit the original sidelink data; the second frequency domain resource is used to transmit the duplicated sidelink data.