$('input[name="IS_BREAK"][value="0"]').prop('checked',true);
<div class="form-group">
<label class="col-sm-2 control-label">单选框验证:</label>
<div class="col-sm-3">
<input type="radio" value="1" name="IS_BREAK" />是
<input type="radio" value="0" name="IS_BREAK" checked />否
</div>
</div>
$('input[name="IS_BREAK"]').change(function(){
if ($('input[name="IS_BREAK"][value="1"]').prop("checked")) {
console.log("true");
} else {
console.log("false");
}
})