Supervisor continues to boss me around long after I left the university I have submitted the PhD thesis for examination more than 2 months ago. I am currently working with full time job as a researcher in industry. While I am still subject to my supervisor as I have yet to undergo viva voce, I am tired with how my supervisor is treating me now. She likes to boss me around with work at university. 

She asked me to provide training to new PhD students in the lab. While I don't really mind do it during my free time (i.e., weekend), she forced me to do it as soon as possible so that she can get the results and publish them in short time. This has led me to ask for leave from company just so I could demonstrate lab techniques to her new students. 

Furthermore, she nonchalantly gave my phone number to new grad students to contact me should any problems arise in the lab without my permission. To make things worse, I was the one held responsible to troubleshoot the problems if the experiment was not successful. Also, she just e-mailed me any papers or manuscripts for me to analyze/check the statistics without me being involved in the project. Then I found out that she didn't even acknowledge me when the paper was published (as co-author/ acknowledgement section).

I am tired of the way she's been treating me. I know I am still bound to her as I have yet to undergo viva. I am scared to tell her that she needs to back off as this will definitely affect my viva voce. What should I do?
To be frank about it, your main problem is that it is not long enough after you've left the university -- i.e., you've submitted your thesis but haven't defended it yet.

Taking a job in between your thesis submission and successful defense sounds inherently awkward to me: what happens if your defense isn't successful?  But I gather that having a such a long gap between submission and defense (in my neck of the woods, we are happy if students send us their thesis three weeks before they defend it) is standard in your part of the academic world.

Did you discuss how you would be spending the time between submission and defense with your advisor before you took the job?  If not, now would be a good time to have that discussion.  I agree with a comment above saying you should try to set boundaries.  I think "Because of my full-time job..." is a promising start to an explanation of why you can't do everything she wants.  You wrote


  This has led me to ask for leave from company just so I could demonstrate lab techniques to her new students.


That seems like a more drastic step than talking to your advisor about this. If you are willing to go on leave from your full-time job, then where are you going to draw the line?

However, I have to counsel you to have this conversation with your advisor carefully: assuming that getting the PhD is important to you for the rest of your career and life (a fair assumption given your situation, I hope!), the truth is that your advisor has as much power over you now as she has ever had.  If you have a terrible falling out with her, that could make her look over your thesis in a different light and -- while personal disagreements with your student should not turn an acceptable thesis into an unacceptable one -- there is some risk of that happening, I'm afraid.

Coming back to the first sentence: you're in an awkward, but temporary situation.  I would suggest working overtime (literally?!?) in the short run to make sure that you both get your PhD and keep the job you want.  Hang in there until you get everything you want.  Good luck.