你想要的是add_role()

这个Codex provides sample code:

$result = add_role(
    \'basic_contributor\',
    __( \'Basic Contributor\' ),
    array(
        \'read\'         => true,  // true allows this capability
        \'edit_posts\'   => true,
        \'delete_posts\' => false, // Use false to explicitly deny
    )
);
if ( null !== $result ) {
    echo \'Yay! New role created!\';
}
else {
    echo \'Oh... the basic_contributor role already exists.\';
}