Can i use 1 controller for both Phantom 4 i own?

Not at the same time.

Hi, good day bigal66. Thanks for reaching out. We do not recommend using 1 controller for 2 Phantom since there is no information as of this moment that the 1 controller will work for 2 drones. We highly recommend using one controller at the same time. Thank you for understanding and have a safe and happy flying always!