As for what you really want, which is one <shiporder ...> element containing all the content of all the files (that is, combining the "shipto" elements from all the input files into one "shiporder"), that's a different plan from what I was suggesting, and it would be best to use a parser for that.

In fact, it seems like the OP code is really pretty close to what you want. Here's my version, with Digest::MD5 thrown in to eliminate duplicate "shipto" content:

#!/usr/lib/perl
use strict;
use warnings;
use Carp;
use File::Find;
use File::Spec::Functions qw( canonpath );
use XML::LibXML::Reader;
use Digest::MD5 'md5';

if ( @ARGV == 0 ) {
    push @ARGV, "C:/file/dir";
    warn "Using default path $ARGV[0]\n  Usage: $0  path ...\n";
}

# open an output file whose name won't be found by File::Find
open( my $allxml, '>', "all_shiporders.xml.combined" )
    or die "can't open output xml file for writing: $!\n";
print $allxml '<?xml version="1.0" encoding="UTF-8"?>',
    "\n<shiporder xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instanc
+e\">\n";

my %shipto_md5;

find(
    sub {
        return unless ( /[.]xml\z/i and -f );
        extract_information();
        return;
    },
    @ARGV
);

print $allxml "</shiporder>\n";

sub extract_information {
    my $path = $_;
    if ( my $reader = XML::LibXML::Reader->new( location => $path )) {
        while ( $reader->nextElement( 'shipto' )) {
            my $elem = $reader->readOuterXml();
            my $md5 = md5( $elem );
            print $allxml $reader->readOuterXml() unless ( $shipto_md5
+{$md5}++ );
        }
    }
    return;
}
[download]

<?xml version="1.0" encoding="UTF-8"?>
<shiporder xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<shipto>
    <name>johan</name>
    <address>Langgt 23</address>
</shipto><shipto>
    <name>benny</name>
    <address>galve 23</address>
</shipto><shipto>
    <name>kent</name>
    <address>vadrss 25</address>
</shipto><shipto>
    <name>stewart</name>
    <address>vadrss 25</address>
</shipto></shiporder>
[download]

Hi, In the script MD5 is no use because I dont have repeated nodes with same content, I have repeated nodes with one tag element, can you help me with that how to remove node information by searching that tag element.please help me with this problem. I am not able to implement logic.

I am not able to implement logic.

I don't know what that is supposed to mean (unless it means that you really don't know how to write program code, and you're unwilling to try).

In the script MD5 is no use because I dont have repeated nodes with same content, I have repeated nodes with one tag element

I don't know what that is supposed to mean either. Are you able to show a show an exact example of what "repeated codes with one tag element" would look like? Can you at least describe how you would recognize the kind of content that needs to be removed?

If you know how to describe the task clearly, that's just the first part of "implementing logic"... If you can't do that, then I guess we're done, and you should find something else to do (and find someone else to do this job instead of you).