Taking basic parameters of flat folding table structure as the breakthrough point, uses geometry reasoning and multi-objective constraint solving method to establish the objective function and constraint conditions, obtains the optimal processing parameters of flat folding table, and by the moment balance principle, the test verifies the stability performance of folding table with the optimal processing parameters. The result indicates that the stability performance of flat folding table is best when IOS surface of the most lateral table leg and the middle table leg is regular triangle.