I am on F1-Visa and filed my 1040NR in last 5 years. My wife joined me two years ago on F1. We both have W-2 income. Can we file our 2017 Tax together using 1040-EZ?

It depends on your situation.  As a F1 visa holder, you are considered as a nonresident for five years from the year you first enter the US.  Starting from January 1 in the 6th year, you are considered as US resident for tax purposes if meet the Substantial Presence Test SPT.  In your situation, if you meet the SPT in 2017, you will be treated as a resident for 2017.  As your spouse is still considered as a nonresident ( does not fulfill the five years rule), if you want to file together, you can make an election to claim her as a resident.  Please see Nonresident to resident

This way, you both are US residents for tax purposes and be able to file jointly.  In the TurboTax program, as you enter all your information, the software will guide you through the step-by-step instructions and create the correct Form 1040 ( 1040EZ or 1040-A or 1040)  which is in compliance with the IRS regulations.