I got below methods from different sources
This is fact that to backup of word press based website is very essential
and yoou need complete step by step instructions,
In the plugins section of your WordPress backend, search for "WP-DB-Backup".
Install the plugin and follow the instructions. It's a super easy-to-use plugin which
will backup your entire database. You can also set it to run at certain intervals (ex. daily)
and email the file to yourself. This plugin will only backup the database. To backup your theme folder,
simply download the theme folder via an FTP client. You will only need to do this when/if you make changes to your theme.
Use an ftp program to download the html_public folder to your computer.
Use cpanel - phpmyadmin to export the database.
If the database is too big for phpmyadmin, look for a program called mysql dumper.
You should find it on a german site, but there is an english section to download it from.
Use the FTP program to upload the files to the html_public folder on new host.
Use cpanel - phpmyadmin to import the database you exported.
And your good to go - you might have to edit the wordpress config file to reflect any database - username - password changes.
But if your moving to a new host, any host worth its salt should move your site for you. Just about all host will move your
sites for you - within a reasonable limit of course.If both host use WHM (web hosting manager) - there is a Transfer site
feature in the WHM. You just need the WHM username and password to both host. It will transfer everything - email accounts,
databases, files,,,,, everything. WHM has a drawback though, its not able to transfer huge sites. If your site is over 5 or 10 gigs,
then WHM will time out.
If you are changing to a new server but same domain, all you need to do is edit wp-config.php and upload everything as it is to your
new server.Easier way try WP-DB-Backup plugin.
if you have any other suitable method please post here below