Hey
when i takeoff and start climbing soemtime later during the climb my aircraft nose go up which lead to de spin ?
Does anyone knows what the problem is

You should set your pitch before taking off

Do you have any flaps in on take off.  Usually with the big jets I will use about 15 degrees of flaps for extra lift.  The once airborne clime at about 2000 - 2500 fpm with full throttle and one notch of flaps to give myself a little help with turns to headings and so forth.  Once established in my climb I can get rid of the flaps.  As long as you are at 250 knots you should have no problem maintaining a climb.  Trim for me is on my joy stick the 2 & 3 button.  If you find your airspeed bleeding of while climbing lower the nose to pick up speed again.  So you may be climbing at 1500 fpm or less.