Your DD214 is your military record. You may need it for any number of reasons, but losing it is not the end of the world. There are ways to obtain copies of your DD214 if yours has gone missing.
Contact the last base you were on. Often they will have a copy of the DD214 for you.
Contact the veterans' affairs office in your area. They often will have a DD214 on file for you for any programs that you have participated in.
Log onto the Records of Veterans Affairs website to get a new DD214 -- find a link in the References section. You can initiate your request for a copy of your DD214 electronically there.
Fill out the information that is needed on the website.
Download and print the application to request a new DD214.
Sign and date the application.
Send the application and any other documents in for processing to get a replacement DD214. These must be processed within 20 days of the initial online request for your copy of a DD214.