Aiming at the shortcomings of annular channel magnetorheological (MR) damper such as the short effective length of damping channel，low damping force，limited movement distance，the annular channel damper was improved based on technical requirements of MR damper．The annular line damping channel MR damper individual designed was proposed．The new MR damper was compared with the annular channel damper, and mechanical model of the new MR damper was established．The damping channel gap h of new MR damper was theoretically researched started from the point of damping force．Finally the MR damper and annular channel damper were established of model, and the relation curve of electric current and damping force was compared and analyzed with MATLAB software. The results of comparison show that the output damping force of new MR damper over the annular channel MR damper is about more than two times.