The present invention discloses a method and a spectrum water generator for processing water with an electromagnetic field, wherein the spectrum water generator comprises a water pipe 1, iron core 2, coil 3 and control circuit, said iron core 2 is a ring-form iron core 2 with air gap 4, said iron core 2 is made up of D44 silicon-steel sheets; said water pipe 1 is plugged in said air gap 4; said coil 3 is placed at both sides of said air gap 4, the input and output ends L1, L2 of said coil 3 are connected with control circuit, the control circuit is connected with power supply. With the spectrum water generator of the present invention, tap water and drinking water can be processed into high-quality water of high oxygen intensity, smaller water particles, and permeates into the human body through drinking or shower, thus improves the micro-circulation of human body and achieves the goal of heath keeping and disease treatment.