I need a software to simulate the op amp circuits, I have Multisim but there are a lot of devices are not included in it's library.
You can try ADIsimPE or LTSpice, or you have special requirements for the simulator?
I tried LTSpice software, it is good, but I don't know if there is a software that has a library that includes most of the op-amps.
If you mean op-amps of most world manufacturers this is serious problem because, as far as I know, not all devices have spice model
If you describe your problem more detailed perhaps I can help you.
Actually, I am trying to learn op-amp circuits design, so that I need some software that is good for this purpose, can you advise me please?
LTspice is probably your best option. The library includes a generic op-amp (near ideal) model as well as probably the broadest range of real op-amp models given the range of LT and AD part numbers built in.
I'm assuming you are talking about designing circuits that use op-amps and not what is inside an op-amp at the transistor level.
If you are interested in transistor level simulation then LTspice is still a good option. You might be interested to have a look at these Wiki pages: