This invention discloses a car suspended damp matching test method and system based on a magneto-rheopectic technology, in which, the system is composed of an up-sprung mass, an unsprung mass, a spring, a magneto-rheopectic damper, a force sensor, a shift sensor, a switch analog switch of an outside peak test module and a feed back controller. Before testing, related voltage signals are got by designing necessary recovered damp value and the compressed damp value of the magneto-rheopectic damper, when an operation head moves up and down to excite the system and the shift sensor tests the relative signal peak value of the piston, the relative voltage signals are input to the feedback controller as the given value by the switch analog switch to control the damper to reach the designed recovered damp value, the compressed damp value and the optimum matching.