The invention provides a method, control device and system for local exchange, wherein the method comprises the following steps: detecting whether voice versions of self-adaptive multirate coding and decoding devices used by devices needing to conduct local exchange are the same and whether the rate sets of the voice versions of the self-adaptive multirate coding and decoding devices have an intersection; if the voice versions of the self-adaptive multirate coding and decoding devices are the same and the rate sets of the voice versions of the self-adaptive multirate coding and decoding devices do not have the intersection, revising the rate sets of the voice versions of the self-adaptive multirate coding and decoding devices and enabling the rate sets to have the intersection; establishing local exchange between the devices with the same voice version of the self-adaptive multirate coding and decoding devices, wherein the rate sets have the intersection. According to the method, control device and system for local exchange, an MS utilizes AMR voice versions to conduct local exchange while full play is given to the function of an AMR to improve voice quality.