How does php generate an word document from a rich text string?

problem description

I now have a rich text string,
such as $str= "

< hr/ >

qq Q Baidu URL

(base64 coding of very long pictures) >

;
I omitted a lot of picture base64 coding.

the environmental background of the problems and what methods you have tried

related codes

/ / Please paste the code text below (do not replace the code with pictures)

I found relevant methods on the Internet, such as this:
first create a class:
class Exportword
{

function start()
{
    ob_start();
    echo "<html xmlns:o="urn:schemas-microsoft-com:office:office"
    xmlns:w="urn:schemas-microsoft-com:office:word"
    xmlns="http://www.w3.org/TR/REC-html40">";
}
function save($path)
{

    echo "</html>";
    $data = ob_get_contents();
    ob_end_clean();

    $this->wirtefile($path, $data);
}

function wirtefile($fn, $data)
{
    $fp = fopen($fn, "wb");
    fwrite($fp, $data);
    fclose($fp);
}

The code that

}
then implements is as follows:
$exportWord = new Exportword ();
$exportWord- > start ();
$fileName ="my study Notes". Date ("Y-m-d Hpuri"). ".docx";
$wordPath = $save_path. $fileName;
echo $str;
$exportWord- > save ($wordPath);
ob_flush (); / / refresh the cache
flush ();

before each execution

what result do you expect? What is the error message actually seen?

after this execution, the file is generated, but there are two problems.
question 1. The image of the generated file can not be displayed (not displayed properly), and other rich text information can be written into the word document normally.
question 2. When the generated file is opened using office, there will be an error and cannot be opened, but it can be opened using wps. Why?

ask God to help me solve the above two problems, or not to use the method above, whether there are other ways to convert rich text to word, and use office to open it normally, and the content will display normally.