problem of car weight & damper spring setting

if the car weight unbalance then the setting of 4 spring also different is that right?

correct~

Differ, but not too much.

At the least, the four springs and shock oil you used should be the same.  Spring rate(how hard the springs are compressed) should be similar too.

If you need huge difference to achieve the desirable ride height, then you should try to 'balance' the car weight(by lead or better placement of weight onboard) first; before making huge changes on damper setting.  Or else, your car might perform quite unpredictably.

Thanks all ching ~