In forge process of hub for GM (General motor) with the revenue is supposed that 43~72Yuan/piece the profit point will become smaller. At 72 Yuan/piece the point is 1.8 piece. Meantime with the product step being bigger the biggest total cost will increase too. αˎ β &γ is calculated to 1.12 ˎ -0.12 & 5 respectively. The least total cost is 100Yuan each minute at the turning point. The biggest total product and capital margin product & average product increases as the labor and capital increase. The effective turn is TP>AP>MPL>MPK to total cost and quantity. The biggest AP increases from 3.5~4 to 6~7 pieces whilst the biggest MPL increases from 3.5~6.5 to 6~11with γ becoming from 3 to 5.