Processing chamber is important part of high-frequency electromagnetic, water processor, In order to determine what kind of processing chamber has better effect to the anti-scal, the paper simulates electromagnetic energy distribution in two common processing chambers by using the software Ansoft Maxwell, which is based on the finite element method. One processing chamber is set with coaxial electrodes and the other one is wrapped by spirals, both are composed by high-frequency electromagnetic pulses. According to the simulation data, electromagnetic energy of processing chamber with coaxial electrodes is much bigger than that of spiral wrapped process chamber. Meanwhile, a mini–circulating water system is built and water quality experiments are completed. Analysis results from experimental data illustrate that two kinds of processing chambers under high-frequency pulsed field have anti-scaling effects, but the processing chamber with coaxial electrodes is much better.