When the model far from camera, the texture on its surface gets distorted

[zhouchangju]

Hello there!
I’m loading a model(a round base with a blue circle on its surface) made by the colleague. When I set a normal scale for it, it looks well:

But when I scroll mouse wheel to make it far from the camera, the blue circle on its surface will be distorted, like this:

Could any one give me some advice? Thanks.