How do I know whether it's TX1 or TX2

How do I know whether it’s TX1 or TX2 ? in CPU part.

What do you mean “in CPU part”? From “/proc/cpuinfo”? Or from something else?

yes, how to know this device is TX1 or TX2?

You may check this https://devtalk.nvidia.com/default/topic/1014424/jetson-tx2/identifying-tx1-and-tx2-at-runtime/post/5171114/#5171114.