In order to add a new admin user please go to Admin Panel >  System > Permissions >  All Users.

Magento 2 New Customer,Admin Panel

Press the Add New User button.

Magento 2 New Customer,Add New Customer

Account Information

1. In User Name set the name of the user which will be used during a login.

2. In the following fields, you have to set user First and Last NamesEmail, Password, and the Passport Confirmation.

3. In Interface Locale you choose the language of the admin panel interface for the user. We recommend selecting English as far as Magento has some issues on other locales. If you decide to choose some other language make sure the language pack of a selected language is installed on your Magento 2 shop.

4. Make user active in This account is select box.

Magento 2 New User,Account Information

5. Enter the current password of a user you are logged in under in the Your Password field.

Magento 2 New User,Password

Afterwards please go to User Role section and choose the role you want this user to be linked to.

Magento 2 New User,User Role

Once you have finished don't forget to press the Save User button.

Magento 2 New User,Save User