This paper presents a method aimed at controlling free surface flow and stirring melt via a magnetic field induced by the permanent magnets. The rotating magnetic field (RMF) can realize the free surface shape control and the melt stirring simultaneously. Numerical model was built to analyse the magnetic field distribution. Two drivers that have the same structure were analysed and optimised. Quasi-steady-state free surface was obtained by regulating the rotating velocity of the magnetic drivers, which is proportional to the magnetic force. Solidification experiment was preformed on a platform of a mini-continuous caster. The solidifying front was observed via addition of a small quantity of Sn-wt.43%Pb into the continuous casting alloy Sn-wt.3.5%Pb, it was found that the solidifying shell grows uniformly under the condition of a proper imposition of the double-permanent-magnet-driver.