If you can match the instrumental version of the song to MusicBrainz I expect there will be the required links to the vocal version of the song even if it does have a different name. In MusicBrainz you should have a relationship linking the two.
For example here we have the instrumental version of Billie Jean by Michale Jackson, and as you can see if you click on the link there is a relationship called instrumental recording of which links it to the vocal version.
I'm not clear if when you say
but the name of this instrumental music is different from the original
if you simply mean the name is different to the vocal version, or if the name is just completely unknown i.e Track 1
But if it is unknown you can use a Music tagger that can identify songs by acoustic fingerprinting.
For example I am the developer of the SongKong Music Tagger, and this can identify songs by acoustic fingerprints to MusicBrainz songs, you should then be able to look up the song on MusicBrainz to identify the vocal version. SongKong is available for Windows, OSX and Linux.