"I have J-1 hardhsip waiver pending and recently I applied for adjusment of status. Will the USCIS approve my EAD while my J-1 waiver and adjusment od status are pending?"
I doubt that they will approve the EAD and I am certain that you will get an RFE for having filed the I-485 before you had obtained the waiver.
PROFESSOR OF IMMIGRATION LAW for over 10 years -- This blog posting is offered for informational purposes only. It does not constitute an attorney-client relationship. Also, keep in mind that this is an INTERNET BLOG. You should not rely on anything you read here to make decisions which impact on your life. Meet with an attorney, via Skype, or in person, to obtain competent personal and professional guidance.
J-1 visa holders subject to 212(e) are not eligible to file for ajustment of status. You needed to obtain J-1 waiver approval before filing the I-485 application. Most likely, USCIS will deny your I-765 since you are not eligible to adjust status.