Semiconductor melt is electrically conducting, which makes it possible to apply magnetic fields to control the thermocapillary convection induced by surface tension in the floating zone under microgravity, and ultimately to control grown crystal quality. In the present paper, based on the comparison between the transverse static magnetic field and the rotating magnetic field(RMF), we focuses on the effects of RMF on thermocapillary convection. Results indicate that in the RMF, the induced Lorentz force is effective in stirring the melt in the azimuthal direction and suppressing axial convection, and both effects are beneficial for the three-dimensional melt convection returning to a steady axisymmetric flow. The RMF is a promising method for convection control in floating zone for semiconductor crystal growth.