eadminecmseditorinfoeditoreditordialog/fck_link.html

查找

input id="txtTargetFrame" style="width:100%" type="text" onkeyup="OnTargetNameChange();" onchange="OnTargetNameChange();"

改为

input id="txtTargetFrame" style="width:100%" type="text" onkeyup="OnTargetNameChange();" onchange="OnTargetNameChange();" value="_blank"