This problem is so weird,the normal map will make the surface shape. I had tried turn the Normal map to non-color and turn on shade smooth. However,they do not work.
Thanks for helping!!!
Welcome to the community 
Can you share a picture of the normal map itself?
Welcome 
…
…this looks like… the normal map does not realy have soome additional info to show… more like the difference between a flat and a smooth shaded model…
…so… is this a proper normal map you are using… ??
This can have different reasons. It might be that your normal map strength is too weak so that the flat normals orientation influences the result, the flat face still shows through.
It might also be that the normals are separate per face ( face corner) , like with custom split normals or separated faces. Is this an imported model? Check if you have custom split normals and delete them testwise.
Third option is that it might also have happened with a similar problem as the second case but at baking stage. Then the problem went into the normal maps texture and the problem should be visible there. Its then dependent on the setup of the baking software you used.