Since almost large die surfaces are free-form surfaces, currently, these are almost manually implemented. In order to overcome this barrier, floating polishing is a feasible polishing technology. The contact pressure between grain and workpiece is a key problem of floating polishing technology. This paper focuses on contact pressure between grain and workpiece. At first, study the friction bound condition between grain and workpiece by ANSYS analysis software, then, compare with the analysis results of slip-line field theory and the test results of single grain. The results show the feasibility of the hypothesis of full friction condition. Finally, study the contact pressure between polishing disk and workpiece using the analysis results of single grain. The research achievements will be used for developing the floating polishing.