In　order　to　solve　the　problems　in　further　development　of　heavy　load　angualarly　deflecting　milling　head,　an　integrated　research　method　which　combines　experimental　validation　and　theoretical　analysis　under　many　styles　of　constraint　was　introduced.　In　theoretical　analysis　aspect,　modal　analyses　of　milling　head　in　the　two　kinds　of　states,　namely,　the　appending　state　and　the　real　working　state　were　carried　out　respectively,　which　mutually　validate　the　correctness　of　theoretical　analysis　under　these　two　styles　of　constraint.　In　experimental　research　aspect,　modal　experiments　were　carried　out　with　freely　supported　box　and　with　initially　wholly　fixed　milling　head　respectively.　Experimental　and　theoretical　analysis　results　were　compared　and　discussed.　So,　exact　modal　characteristics　of　milling　head　and　unsubstantial　segments　with　its　influencial　factors　were　gotten,　which　provide　theoretical　and　experimental　support　for　structural　optimization　and　improvement　of　heavy　load　angularty　deflecting　milling　head.