constantly consuming high CPU i want to use software to monitor my network, the monitor process is consuming 20% CPU times, is it any impact to my device except battery life?

If a program constantly consume high CPU, will it create a lot of heat and ruin the device ?
Constant battery use will generate more heat over a short period of time, yes.  Ordinarily, this will not damage the device.  However, heat can greatly impact the longevity of your battery.  I would suggest shutting off the monitor when you don't need it; if you really need to constantly monitor the network, the task is probably better suited to a PC.