A　new　MR　brake(MRB)　was　designed　for　traction　elevator　because　of　the　shortcomings　of　the　existing　traction　elevators　with　machine-electric　brake-high　operating　impacts　and　high　noise.　The　device　had　a　dual-coil　structure,　which　also　designed　channels　for　the　circulation　of　coolant　liquid　for　integral　heat　radiating,　satisfying　elevator　braking　with　large　braking　torque　and　good　heat　dissipation.　Based　on　mathematical　model　in　heat　transfer,　the　numerical　simulation　analysis　was　performed　for　thermal　field　of　MRB　in　no-load　operation　conditions　and　in　typical　emergency　braking　situation　with　finite　element　software.　The　work　improved　heat　dissipation　by　using　water　cooling,　revealing　the　temperature　changing　regularities　under　typical　condition　of　key　parts.　The　reasonable　working　temperature　range　was　verified　with　test　methods.　Simulation　and　experimental　results　show　that　temperature　has　a　greater　impact　on　braking　mechanics　performance;　however,　the　device　can　satisfy　the　requirements　of　the　elevator　operating　with　the　effective　cooling　conditions.　©　2016,　China　Mechanical　Engineering　Magazine　Office.　All　right　reserved.