咱们不是第一个有这个疑问的，看里面这个问问题的，乐s我了：

How do cats recognize their owner?
I tried to fool my cat, who waits for me everyday by the driveway (hot/cold/snow/rain/storm).

I tried hiding my head in my coat.
Parking the car far away and walking home under a blanket downwind.
Even tried making strange sounds while approaching the house.
Always knows its me.

There are many people that go by the house and through the house, but somehow the cat can distinguish me from the rest.

Even a human cannt tell who the person is if under a blanket.

Additional Details
"downwind' means he cannt smell me.
"through the house" means other people make up most of the traffic into the house.

I have roomates and guests all the time.
the cat dilligently watches post until I come home. The house has a shared walkway with other neighbors. Traffic is high. I dont come home at any given schedule.

Best Answer - Chosen by Voters
my cats know the sound of my footsteps, even when I was using crutches. All animals can sense thier owners I think....there was an Animal Planet special once about how dogs and cats cansense thier owners from even a mile away - and one rides a bus that lets her off a 1/2 mile from her house - but the dog always woke up and went to the door to wait (even thou it was a different times of the day). After a year of being gone in the military, my son's cat went crazy at the door, just like he used to when my son came home from school, about 20 minutes before he walked in the door.....it was suppose to be a surprise for me, but I knew when Monster started going nuts, my son was close by.