let example = $('#example').DataTable({
    columnDefs: [{
        orderable: false,className: 'select-checkBox',targets: 0
    }],select: {
        style: 'os',selector: 'td:first-child'
    },order: [
        [1,'asc']
    ]
});
example.on("click","th.select-checkBox",function() {
    if ($("th.select-checkBox").hasClass("selected")) {
        example.rows().deselect();
        $("th.select-checkBox").removeClass("selected");
    } else {
        example.rows().select();
        $("th.select-checkBox").addClass("selected");
    }
}).on("select deselect",function() {
    ("Some selection or deselection going on")
    if (example.rows({
            selected: true
        }).count() !== example.rows().count()) {
        $("th.select-checkBox").removeClass("selected");
    } else {
        $("th.select-checkBox").addClass("selected");
    }
});

我已经添加到CSS了：

table.dataTable tr th.select-checkBox.selected::after {
    content: "✔";
    margin-top: -11px;
    margin-left: -4px;
    text-align: center;
    text-shadow: rgb(176,190,217) 1px 1px,rgb(176,217) -1px -1px,217) 1px -1px,217) -1px 1px;
}

工作JSFiddle,希望有所帮助.