Airdrop problem between Macbook & i6plus

My Macbook running OS X El Capitan 10.11.4 cannot connect with my iPhone 6 plus 9.3.1 by using Airdrop, they both can't find each other, even just using bluetooth connection can only connect for 1sec then disconnected automatically. I have tried log in & out the icloud account, restart both device, turn on & off bluetooth, checked the firewall is disabled, however still not working.