使用Codeigniter 3无法在URL中获取参数

I am trying to get the parameter I passed in my URL using the GET but I have an error:

An Error Was Encountered

The URI you submitted has disallowed characters.

My URL is looks like this:

http://localhost/teradasys/index.php/users/user/user_info&user_id=1

And in my controller:

public function user_info() {
    $user_id = $this->input->get('user_id');
    print_r($user_id);
}

How can I fix this?

You URL is missing the ? which defines the start of a query parameter. Therefore your URL should look like this http://localhost/teradasys/index.php/users/user/user_info?user_id=1. Then you can use the get() function.