What's the procedure going to be after forms i130 and i485 were submitted and accepted then us citizen spouse dies?

You will need to submit a written request to USCIS asking for Section 204(l) Relief. This Request must include the following information: (1) your name and your deceased spouse's name; (2) your alien registration number (A number), if you have one; (3) your deceased spouse's A number, if he/she had one; (4) the receipt number on your petition or application; (5) your spouse's death certificate (a certified translation is required, if not in English); (6) proof of your residence (examples include, but are not limited to: lease/mortgage, utility bills, pay stubs, school records, etc.) at the time of your relative’s death up until the present time; and an affidavit of support from a substitute sponsor or an affidavit of support exemption, if applicable. You may also be able to self-petition as a widow. I encourage you to consult an attorney.