My advice (never having been there before) is to take it slow and build his confidence in sleeping in his own bed. After all, he is probably unsettled from the move and needs reassurance. Do you fit in there too? You could try lying with him for day naps, reading stories on that bed, playing with toys there etc. Make sure you have a good bedtime routine to wind him down into sleep there. The more he knows what to expect the more confident he will be. Has he got any comfort items like a favourite toy to sleep with? Maybe the toy could start 'having day naps' there. You could put in a nightlight and some music on to help him settle in. Make sure he knows you are close and will come if he gets upset and he will get his confidence back.
I hope this helps.