My horse is pushy in the field and trots at me anyone can help?

How old is he? Has he always been like this? If this is when you are going to catch him he might not just want to be caught, hide the halter and lead behind your back and take a treat in with you. He seems like he does not respect you, how loong have you owned him for? This is a problem that comes with alot of horses, this does not mean they are bad they are just difficult to catch, the rearing is a problem and can be dangerous for you, confront him from the side and wrap the lead around his neck when you catch him, give him a treat whilst you put the halter on, train him so he knows if he comes and is good he will get a treat, basically like teach a dog to sit. He is probably just being pushy and you need to show him your the boss but you cant let him get away with these things anymore as he is just going to keep going and think you cant handle him, take someone else in the paddock with you, preferably an experienced or a strong person. When i was young my horse used to do this and my dad would have to help me, but eventually she knew to stop pushing me around cause i was the one with the carrots ;) but you will probably find they will still have a few stubborn cheeky days, just be careful and try and relax him by using the T-Touch method, on his neck near the roots of his mane scratch in a circular motion, i hope i helped.