A cochlea electrode arrangement, system and method for enhancing musical melody perception. On each cochlear basilar membrane, according to the characteristic frequency correspondence of music notes, a phonosensitive full spectrum band corresponding to the cochlea apex to cochlea base is divided into musical response areas in response to specific musical note stimulating signals; a corresponding electrode for conducting or sensing frequency band signals is placed in each musical response area, namely, each electrode is placed in the corresponding characteristic frequency band where the music notes are located, the electrodes are divided into two groups, and a corresponding group of electrodes is implanted into cochleae on two sides respectively. Due to the fact that the electrodes are arranged in the cochleae on the two sides, the cochlea electrode arrangement is easy to implement, and the electrodes arranged in the cochleae on the two sides can perceive music better.