The invention relates to a linear echo control method, and its kernel: detecting the carried signal on the current link; when confirming the service is a low-speed data service according to the detected signal, enabling EC (echo counteractor) and simultaneously closing NLP (nonlinear processor), and stopping the linear echo control. Thus, it can assure being able to control to close NLP while enabling EC in NGN structure so as to avoid data service failure. When fax service adopts T38 mode and channel state is switched from T38 state to voice state, it can reinitialize EC parameters, thus able to improve voice quality by EC. In addition, it keeps the states of EC and NLP until the service ends, thus avoiding the data service failure caused by re-enabling NLP. |