I have a problem that when I fetch surface data from fluid object and connect it to data input of other objects node,but it says “connection to input 1 is wrong type” why?How can I set correct connection?

hey there,
your graph looks just wrong, that's not the way you're supposed to use the fetch data DOP. If you want to have your fluid colliding with geometry you need to attach a solver to your rbd object (either static or rbd solver i.e.) and plug that into a merge node and connect the fluid solver to the same merge node.
You'd use to use the apply data node to attach forces or a modify data DOP, you could read that up in the documentation

regards,

Manu