The invention discloses a mechanism movement accuracy reliability analysis method based on a fuzzy out-crossing model. The mechanism movement accuracy reliability analysis method includes the steps of (1) building a generalized fuzzy random stress-strength interference model (please see the specifications for the model) according to task characteristics, (2) determining a subordinating degree function mu(x) of movement errors, (3) determining the reliability R(tau0) at the moment tau0, and calculating the complete up-crossing rate v+(tau) and the complete down-crossing rate v-(tau), and (4) calculating the fuzzy time-variation reliability R in the mechanism task executing process. By means of the mechanism movement accuracy reliability analysis method, influences of the errors and tolerances of mechanism movement on the mechanism accuracy reliability are considered, a time-variation reliability calculation method-PHI2 and a state fuzzy analysis method are combined, and the mechanism fuzzy time-variation reliability problem can be effectively solved; the aim that in a classical mechanism movement reliability theory, when the time-variation performance and the fuzzy performance are considered at the same time, the failure probability is calculated by properly changing the out-crossing model is achieved.