DataTable dt   //你的DataTable数据

DataView dv = new DataView(dt);//视图
DataTable dt1= dv.ToTable(true, new string[]{"CourseId","TeacherId"});//true 表示是去重 string[]是要去重的列CourseId和TeacherId都一样才去掉重复

dt1就是去重后的DataTable

C#Datable去重复