You may be able to import your W-2 if your payroll provider is a TurboTax Import Partner. You will need information from your last paycheck stub to import. From your W-2, you need the information from Box 1 (gross income) or year to date gross income from your last paycheck stub and your employer's EIN.
Other options:
Contact your payroll department to request a duplicate W-2.
Contact the IRS for help at 1-800-829-1040. The IRS can help you with trying to obtain your W-2, or
File a Form 4852 as a substitute W-2 Form along with your tax return, but you will have to mail your tax return.