I am an Indian, I hold a Schengen visa. During my sail in cruise from Fukuoka to Qingado can I enter

You can enter Qingdao on 24 hour visa free transit if the immediate ports of call before and after Qingdao are located in different countries.

For example, if your itinerary looks like:

Fukuoka (Japan) - Qingdao (mainland China) - Busan (South Korea)

Then you are eligible for 24 hour visa free transit and you can enter the city based on this type of transit or in other words, you will be granted a temporary entry permit upon your docking in Qingdao.

Anyway, if your itinerary has another port of call, immediately after Qingdao, in mainland China, then you need a tourist (L) visa obtained in advance. The same thing is if your itinerary has a port of call, immediately after Qingdao, in Japan. This is also not eligible for 24 hour visa free transit and also in this case, you need a tourist (L) visa obtained in advance.