Major logistics companies have been paying most of attentions on the maximization of pallet usage efficiency. The two-dimensional pallet loading problem can be transformed into the orthogonal arrangement of two-dimensional irregular rectangular pieces. This paper mainly studies the hybrid heuristic algorithm combining simulated annealing (SA) algorithm and the minimum horizontal line (MHL) algorithm to solve the two-dimensional pallet loading problem. Since the local optimization ability of the simulated annealing algorithm is relatively strong, and the global search ability of the lowest level algorithm is relatively strong, the two algorithms are combined to solve the two-dimensional pallet loading problem. Experiments show that the hybrid heuristic algorithm proposed in this paper is nearly 17 times faster than the integer programming model in terms of convergence time, and it is also improved compared with the genetic algorithm in terms of convergence time and space utilization.