For solving the integer nonlinear programming problems, a discrete particle swarm optimization(PSO) algorithm
combined with the orthogonal crossover is proposed. In the PSO algorithm, each particle of the swarm is truncated to the
nearest integer after the determination of its new position, and then each particle’s best position till now is repaired by using
a stochastic method to reduce the rounding error. The orthogonal crossover operator based on the orthogonal experimental
design is integrated into discrete PSO algorithm to make a systematic and rational exploration. The inertia weight and
constriction factor are dynamically adjusted to improve the efficiency of PSO algorithm. Some numerical examples with
different dimensions are carried out and the experimental results show the effectiveness of the proposed algorithm.