Substantial research results show that the magnetized water can make the cement hydration reaction more completely, which can increase the cohesion of concrete mixture and enhance the strength of concrete. Therefore, the compactness and water impermeability of the concrete mixed with magnetized water in different degrees are studied in the paper. On the basis of the study of the concrete of magnetized water by the predecessors, a test of magnetized water concrete has been taken based on two selected magnetic parameters, the corresponding magnetic field intensity and water flow rate. According to the principle of cross-test, 21 samples with the intensity levels C20, C25 and C30 are chosen. The tests indicate the different properties between the magnetized water concrete and ordinary water concrete at the condition of same strength to study the special law influenced by the flow speed of water and the magnetic field strength. Based on the test above, the typical samples of the magnetized water concrete and ordinary water concrete have been scanned by the electron microscope. The pictures scanned by electron microscope can help to analyze the microstructure of magnetized water concrete and the ordinary one. The magnetized water can improve the properties of concrete. On the basis of the study of magnetic water concrete by the predecessors, the effects such as hypothesis of the mechanism, action of the cement hydration, concrete workability, water ratio of the concrete, setting time and hardening process of magnetized water concrete was studied in this issue. The mechanism of improvement of magnetized water concrete is also analyzed from the perspective of microanalysis.