How far is the Shanghai Zoo from the main international airport?

What do you mean the main airport? Is it Pudong Airport?

Yes Pudong Airport and the zoo not the wild animal park. Thanks.

Take metro line 2 from PVG to East Nanjing Road Station. Then transfer to metro line 10 to the Zoo, Exit 1. After arriving, walk south to the zoo directly. But to be honest, your layover is short, you are not advised to go to the zoo. Because you need to come back to the airport at least 2 hours in advance.

Thank you! Too short for the wild animal park also?

Yes, the time is not enough to visit the Wild Animal Park also.