I want to apply S1 what application do I need and do I need bank account to show?my sister work in c

When you apply for the S1 type, the bank account is not needed. But if your sister works in PRC, I’m afraid you cannot apply for the S1 type and you can only apply for the S2 type.
S1 type is issued to those who want to go to PRC to visit the foreigners working or studying in PRC to whom they are spouses, parents, sons or daughters under the age of 18 or parents-in-law.