Based on the theory of an electromagnetic field, the physical and mathematic models of a hot-top electromagnetic continuous casting system have been constructed. The little coil method was used to measure the magnetic field of the shaping system under different powers. Finite element software has been used to numerically simulate the influence on magnetic flux density and the distribution in the mold in terms of the height of the inductor and the mold as well as the structure of the hot-top. The results have shown that: 1) reducing the height of the mold could enhance magnetic flux density in the system, but it wasn't obvious; 2) the height of the inductor had a measurable effect on the magnetism of the system (using the inductor with a height of 20 mm could increase the magnetic flux density 85 percent over using the inductor with 40 mm in height); 3) the numerical simulation results with the load showed that the skin effect of the magnetic field was becoming obvious. Hot-top had no obvious influence on the magnetic flux density and distributing rule. It showed hot-top electromagnetic continuous casting technology would be favorable to improve the efficiency of the power and to stabilize the height of the liquid column, and could improve the quality of the interior and surface of the ingot.