var iframe = document.getElementById("print-iframe");

            if (!iframe) {

                var el = document.getElementById("print_content");

                iframe = document.createElement('IFRAME');

                var doc;

                iframe.setAttribute("id", "print-iframe");

                document.body.appendChild(iframe);

                doc = iframe.contentWindow.document;

                //这里可以自定义样式

                doc.write('<div style="width: 500px;">' + el.innerHTML + '</div>');

                doc.close();

                iframe.contentWindow.focus();

            }

            iframe.contentWindow.print();

            document.body.removeChild(iframe);

<div style="display: flex;flex-direction: column;align-items: center">

            <div id="print_content" style="width: 200px;">

                <img style="width: 100%;" t-attf-src="data:image/png;base64,#{widget.value}"/>

            </div>

            <button class="btn btn-primary btn-sm">打印</button>

        </div>