In industrial cycling cooling water system, the dirt of heat exchanger causes enormous economic losses, and the traditional anti-scaling method has disadvantages, such as secondary pollution, poor results and high cost, etc. While the anti-scaling of electromagnetic field is convenient, pollution-free and low cost. These are advantages that other methods don’t have. A high-frequency electromagnetic device with DDS and amplifier technology for different water is designed, and its output is single frequency and sweep of the square wave signal within the scope of 0~1 MHz. A dynamic circulating water system is set up in laboratory to simulate industrial water cycling system. The research results show that external high-frequency electromagnetic field slows down the crystallization rate. Part of original calcite comes into aragonite. In addition, the effect of anti-scaling is effected by the concentration and output frequency, while the higher output frequency doesn’t always obtain better result, and the concentration of calcium should not be more than 5 mmol/L.