The invention relates to a starting-up signal generating device which is coupled to a computer system for controlling the starting up of the computer; the starting-up signal generating device comprises a power supply detection circuit and a pulse generation circuit; wherein the power supply detection circuit is used for detecting a power supply signal and outputting a multi-voltage signal; the pulse generation circuit is coupled to the power supply detection circuit and the computer system for receiving the multi-voltage signal and outputting a starting-up signal to the computer system according to the multi-voltage signal. The starting-up signal generation device utilizes a hardware line to lead the computer system to start up automatically after multi-voltage operation is carried out without software control, the full-hardware structure and the line thereof have simple structure and low cost; meanwhile, when power supplying is restored, the computer system can achieve automatic starting-up rapidly by in the invention; in addition, the error caused by software starting-up program execution can be improved, and the problem of being incapable of re-starting can not caused.