I am a international student and in my fourth year of my PhD studies. My first supervisor left school without any notice in the end of my second year. I waited half year to get my second supervisor who is lack of interest of my subject and cannot give me any proper advise and supervision on my study. My third supervisor is the worst, he keep discourage and want me quit my PhD ASAP because he think that I don't have the ability to finish it. Be honest, I dont have enough supervision in the past three years, and I known that I am still need to make big progress on my thesis. But, quit in the fourth year after I put so many time, money, and effort on this PhD is really not an acceptable opinion!!!

How far along are you in your thesis? If after 4 years you are nearly ready to submit I think you are quite right to hang in there and finish. It will give you an immense sense of satisfaction to achieve your award, and the fact that you had to overcome so much will make it all feel even more worthwhile. To do a PhD under those circumstances is impressive.

However, if you still are at the initial stages of a project, it may be sensible to think about doing something else. I have seen one candidate getting torn to shreds in her viva, because of her "inadequate" thesis which is a horrific way to end six or so years she spent self funding her studies. She was denied a PhD and was awarded an MPhil after another 6 months of ammendments.

I agree with Badhaircut. It depends on the stage of your research.
You have my sympathy. Relationships with supervisors can be very difficult. I would like to stress the importance of tackling the problems at the beginning. I know of people who took three years to complete an MLitt full time, due to problems with their supervision! It is not necessary - nor you should expect -to make friends with your supervisor, but you should get help and support when necessary. I had problems with mine. I had to learn 'to work around' some corners. I now have a new supervisor and I hope that this change will be for the best! What area are you in? Is there anyone you can approach in your department?

Yes, thanks for your kind advice. I am in the middle of my thesis, try to finish it in another few months. I want to hand in the thesis directly to school, but really not sure about the quality because none of the word in this thesis are approved by my supervisor.

You really need to get someone to read it.

Presumably your supervisor HAS to sign off before you submit it. If he or she is even doing 1/10th of what they are supposed to be, then they will have at least read it and provided their suggestions before you submit to the examiners. If this doesnt happen, for any reason, then something is wrong and I suggest you get help from the appropriate university authorities.

Yes, I want them at least take a look at it, but the problem is they doesn't give suggestion or any revision on my work. They only scrutinize my footnotes and interrogate me on my grammar.