关于使用多线程比较数据问题？


 try {
             
                foreach (DataRow row in dtTargetTable.Rows)
                {
                   
                   
                    string ec_khh = row["ec_khh"].ToString(); 
                    string ec_name = row["ec_name"].ToString();  
                    string ec_phone = row["ec_phone"].ToString(); 
                    string ec_tel = row["ec_tel"].ToString(); 
                    string ec_bh = row["ec_bh"].ToString(); 
                    string ec_azrl = row["ec_azrl"].ToString(); 
                    string ec_pbbh = row["ec_pbbh"].ToString();  
                    string ec_xlbh = row["ec_xlbh"].ToString();  
                    string ec_ydxz = row["ec_ydxz"].ToString();  
                    string ec_dbxh = row["ec_dbxh"].ToString(); 
                    string ec_bqzs = row["ec_bqzs"].ToString(); 
                    string ec_bl = row["ec_bl"].ToString();                    
                  
                    int i = 0;
                    foreach (DataRow row1 in dtTempTable.Rows)
                    {
                        i++;
                        //label1.Text = i.ToString();
                        string hh = row1["hh"].ToString();
                        string hm = row1["hm"].ToString();
                        string yddz = row1["yddz"].ToString();
                        string bh = row1["bh"].ToString();
                        string cbxh = row1["cbxh"].ToString();
                        string dh = row1["dh"].ToString();
                        string yddh = row1["yddh"].ToString();
                        string azrl = row1["azrl"].ToString();
                        string pbbh = row1["pbbh"].ToString();
                        string xlbh = row1["xlbh"].ToString();
                        string ydxz = row1["ydxz"].ToString();
                        string zch = row1["zch"].ToString();
                        string dbxh = row1["dbxh"].ToString();
                        string bqzzz = row1["bqzzz"].ToString();
                        string bl = row1["bl"].ToString();
                        if (hh == ec_khh)  //如果目标表中存在相应数据 
                        {
                           
                            isexist = true;                            row["ec_name"] = hm;
                            row["ec_address"] = yddz;
                            row["ec_phone"] = yddh;
                            row["ec_tel"] = dh;
                            row["ec_bh"] = bh;
                            row["ec_azrl"] = azrl;
                            row["ec_pbbh"] = pbbh;
                            row["ec_xlbh"] = xlbh;
                            row["ec_ydxz"] = ydxz;
                            row["ec_dbxh"] = dbxh;
                            row["ec_bqzs"] = bqzzz;
                            row["ec_bl"] = bl;                            row1.Delete();
                            dtTempTable.AcceptChanges();
                         
                            break;
                        }
                    }就是对两张表进行数据比较，因为数据量比较多大概两张在10w数据左右，导致程序运行很慢，请问如何用多线程进行啊。