mesh.vertices of some models not correct.

I use below simple code to get the vertices of a model:

    Mesh mesh = GetComponent<MeshFilter>().mesh;
    foreach (var item in mesh.vertices)
        Debug.Log(name + " V: " + item);

But the result in Console is strange. Only 9 different Vector3 values for such a complex model. It’s definitely not the correct vertices position.
Please help. Thanks in advance.