A new type of supporting structure in a rotor system was presented, where four-axis linkage mechanism, symmetry elastic mechanism and rigidity adjustment mechanism were applied in order to make the precise match, to increase the stability, to prolong the lifetime and to adjust the supporting rigidity of the rotor system.A theoretical analysis was carried out by using the transfer matrix method.The results of the analysis were verified with the help of finite element method and experimental method. The results show that the new type of rotor supporting mechanism can effectively adjust the critical speed of rotor system.