Depending on the Bitrix version, namely the kernel used, the database connection information is contained in different files.
Bitrix with new D7 core
Starting from the “1C-Bitrix: Site Manager 14.0” version, the database settings are stored in the /bitrix/.settings.php file in the “connections” section
'connections' => array (
'value' => array (
'default' => array (
'className' => '\Bitrix\Main\DB\MysqlConnection',
'host' => 'localhost',
'database' => 'admin_bus', // database name
'login' => 'admin_bus', // database user name
'password' => 'admin_bus', // user password
'options' => 2,
Bitrix with old core
In the root directory of your site, find the /bitrix/php_interface/dbconn.php file and find these lines:
$DBLogin = "u1234567_dbuser";
$DBPassword = "password";
$DBName = "u1234567_database";