I need define a safety stock in item master data (ttiitm001.t$stst),but I hope it don't infulence the safety stock in a specific non-nettable warehouse (ttdinv001.t$sfst),by default ,the safety stock value in specific warehouse copy automatic from item master data. I want the value is 0 by default.
if you are expert in this field,please answer me !!!
thank you very much!

It is not possible to do that with the standard system.

Why don't just define the safety stock at the item-warehouse level? Or define the inventory plan at MPS.

I am known I can maintain the item-warehouse safety stock ,but I will need to maintain 10 times if I have 10 non-settable warehouse after I add a new item.if I don't maintain beforehand,when the item first transaction in the warehouse,system will set the safety stock in specific warehouse to item safety stock (ttitm001.sfst),I will encounter the risk of extra addition stock .

You should add saftey stock by warehouse in tdinv0101m000. Items by warehouse. Then, you dont have to worry. If you add the saftey stock to the item master, that is taking the nettable warehouse into account that is on the form 3 of item master.