Abstract: The packing problems，especially three-dimensional components packing problems，can be found in many industrial domains．Because they are known to be a NP-complete problem in theory，they’re too difficult to be solved with traditional optimal methods．The packing of transmitting parts in clocks and watches movements is a three-dimensional components packing problem with more constraints．Simulated annealing is a stochastic optimization technique that has been used to solve continuous，ordered discrete and multi-modal optimization problems．With this algorithm，this paper has successfully solved the difficulty in designing movements of clocks and watches．It also provides framework for solving general packing problems．