Due to the high toughness of SiC material, in general, the polishing time of a SiC mirror has been challenging to determine by optician. In the optical shop, optician normally enters input parameters into a polishing machine prior to polish out the mirror surface. The target surface removal rate, specified by an optician, are highly depending on polishing schedule. A very tight polishing schedule commonly thrusts adventurous larger target quantities on the optician. However, the target numbers should be determined by the reliability of relationships between the machine input parameter and output removal rate. In this paper, we introduce an initial model which can reliably suggest machine input parameters for polishing head. These parameters can control polishing processes to achieve the target TIF (Tool Influence Function) depth which is an unit polishing removal quantity on the SiC mirror optical surfaces.