Any right way to create parent/child listing, combine standalone listing

Hello Guys
When I tried to combine listing and found out the listing data would be wrong
All child stand-alone data/info will be merged into one random pick Asin’s info
I use model number variation, naturally, different child asin have different images and description
but in my case, when the parent asin is created, I try to switch from variation, all the data is the same
Please help