An embodiment of the invention provides a device and a method for digital pre-distortion. The device for digital pre-distortion comprises a nolinear device used for compensating the nolinear characteristic of the signal; a memory effect compensator used for compensating the memory effect characteristic of the signal; a constant value characteristic obtainer used for processing the feedback signal to obtain the constant value characteristic information of the signal; a cost function generator used for calculating the pre-distortion cost function according to the obtained constant value characteristic information and the preset value, wherein the preset value is obtained beforehand according to the modulation mode of the signal; and a coefficient updater used for updating the coefficient of the nolinear device and the coefficient of the memory effect compensator according to the cost function. According to the embodiment, the nolinear and memory effect distortion of the signal can be compensated, the structure is simple and the cost is lower.