Magnetic compound fluid (MCF) polishing process is a fine polishing process that has been applied to a large variety of materials, ranging from soft optical polymers to hard ceramics. With the help of magnetic field, non-magnetic polishing abrasive particles are carried by carbonyl iron particles (CIPs) and remove material from the surface being polished. Knowledge of the MCF slurry behavior and forces acting is essential to comprehend the material removal mechanism. To clarify the MCF slurry behavior under a dynamic magnetic field, investigations are carried out to study the variation process of external slurry shape and the effects of process parameters (magnet revolution radius r, magnet revolution speed n_m and supplied MCF slurry volume v) on the slurry terminal shape formation time T and the diameter W and the maximum height H_max of the terminal slurry shape. MCF slurry with clear-cut shape is achieved and the shape is repeated with the revolution of magnet. The magnet revolution radius r shows significant influence on the slurry behavior. Mechanical characteristics of MCF slurry: normal and shearing forces under the dynamic magnetic field are measured and effects of MCF carrier rotation speed n_c, magnet revolution speed n_m and working gap Δ on polishing forces are investigated. The working gap Δ makes considerable contribution on polishing forces.