i would recommend using the following code.
table.ajax.reload(null, false);
The reason for this, user paging will not be reset on reload.
Example:
<button id='refresh'> Refresh </button>
<script>
$(document).ready(function() {
table = $("#my-datatable").DataTable();
$("#refresh").on("click", function () {
table.ajax.reload(null, false);
});
});
</script>
detail about this can be found at Here