A timing-control method of a hardware-simulating program can be applied to a software platform for facilitating control program development. The hardware-simulating program can be recorded in any suitable recording medium and defines therein a plurality of simulating elements which are automatically synchronized at intervals by setting specified time points as aligning points. The specified time points are set with adjustable intervals. By adjusting an interval between adjacent specified time points, the simulating speed between the adjacent specified time points can be changed to comply with practical requirements.