The invention discloses a linearization device with a memory non-linear amplifier and a linearization method in a broad band multicarrier communication system, and the linearization device comprises a signal trimmer, a self-adapting wave filter, the amplifier, a fader, a tapping coefficient renovator and a request form renovator, wherein transmission signals are respectively reconditioned and filtered by the signal trimmer and the self-adapting wave filter and are output to the amplifier for amplification, then the signals are divided into two groups, one group is sent into a channel for transmission, the other group is sent into the fader until reduced to the electrical level before amplifying, and the signals are further output to the tapping coefficient renovator and the request form renovator to respectively renew the tapping coefficients of the wave filter, amplitude request forms and phase request forms. By repeating the steps and continuously renewing the amplitude request forms, the phase request forms and the tapping coefficients of the wave filter as well as reconditioning and refiltering generated transmission signals, the linearization function of the amplifier in the broad band multicarrier communication system can be realized through the repetition of the steps. The linearization device and method in the broad band multicarrier communication system have the advantages of fast convergence rate, high convergence accuracy and high linearization level.