Based on the structure decomposition of machine tools as function-movement-action, the deviation source that affects precision of meta-action assembly unit was clustered into four types: form error, position error, assembly position error and kinematic error. In order to express the relationship of coupling and nesting vividly, error linkage model was introduced as the basic unit of meta-action assembly unit error relationship to construct structured error relationship model of linkage network and linkage matrix. An assembly error transfer path search method based on error linkage model was proposed, searching all possible paths by mouse maze algorithm, and the effective transfer paths of error component were obtained on the identifying basis of the highest assembly accuracy. Worm axis parallelism error of worm drive meta-action assembly unit was taken as the target to verify the method and the results show that this method is capable of searching all error transfer path efficiently and getting effective path rapidly. This method provides theoretical basis for quality prediction and control of machine assembly.