In orthogonal frequency division multiplexing (OFDM) systems, the genetic algorithm-based partial transmit sequence (GAPTS) technology can effectively reduce the computational complexity of PTS, but it is not ideal in improving the peak-to-average power ratio (PAPR) performance. Therefore, proposing to embed a simulated annealing (SA) operator in the GA to construct a hybrid genetic simulated annealing (GSA) algorithm, and it is also applied to search for the optimal phase factor of the PTS. First, chromosome formed by encoding PTS phase factor, the chromosomes composed of random elements are used as an initial population of the GA, and the fitness value of each chromosome is evaluated. Then, the chromosomes are also selected according to their fitness values, and the mutation rules and the mating (or cross) rules of the chromosomes are established to perform the iterative evolution on the population. Finally, the chromosomes in population are updated with annealing temperatures to produce new next-generation populations. The simulation results show that compared with the GA-PTS, the proposed method not only decreases the computational burden, but also effectively reduces the PAPR value of the OFDM system.