To optimize the component placement sequence of gantry surface mounting machine, a mathematical model of component sequence was established, and the triangular probability distribution shuffled frog-leaping algorithm was proposed with the strategy of selecting several frogs for meme evolution. These frogs were selected according to triangular probability distribution. The presented algorithm was used to resolve the optimization problem of component placement sequence. Experiment results indicated that the improved algorithm outperformed shuffled frog-leaping algorithm in convergence ratio and Genetic Algorithm(GA) in accuracy and convergence ratio. Known from parameter analysis that better solution could be obtained when the frog population number increased and the effect of memeplex number was weaker comparing to frog population number. There was a memeplex number corresponding to different frog population number which ensured the algorithm to be comparatively stable.