可以写个 Web 服务，同一个局域网下手机电脑一般可以互联。比如底下是用 Emacs 实现的，下面的截图就是在手机上截的，然后用这个办法传上到电脑的。
(require 'web-server)
(ws-start
'(((:GET . ".*") .
(lambda (request)
(with-slots (process headers) request
(ws-response-header proc 200 '("Content-type" . "text/html"))
(process-send-string
process
"\
<meta name='viewport' content='width=device-width, initial-scale=1'>
<h1>Upload File</h1>
<form method='post' enctype='multipart/form-data'>
<input type='file' name='file'>
<input type='submit'>
</form>
"))))
((:POST . ".*") .
(lambda (request)
(with-slots (process headers) request
(let-alist (assoc-default "file" headers)
(let ((out (make-temp-file "x-" nil .filename)))
(let ((coding-system-for-write 'binary))
(write-region .content nil out))
(message "[%s] saved %d bytes to %s"
(current-time-string)
(string-bytes .content)
out)
(ws-response-header process 200 '("Content-type" . "text/plain"))
(process-send-string process (format "saved to %s\n" out))))))))
9008 nil :host "0.0.0.0")