条件：B7=B8且都等于0则B9不作显示；B8＝0但B7大于0则B9＝100%；B8大于0则B9=(B7-B8)/B8.

B9=IF(B7=B8,"",IF(AND(B8=0,B7>0),"100%",IF(B8>0,(B7-B8)/B8))
再问： 我还漏了一个条件：B7=B8且都不等于0则B9显示“持平”
再答： B9=IF(B7=B8,IF(B7=0,"","持平"),IF(AND(B8=0,B7>0),"100%",IF(B8>0,(B7-B8)/B8))