Computer microsecond-level time output method and system and calibration system

The invention relates to a computer microsecond-level time output method and system, and the method comprises the steps: firstly obtaining a first time interval from a starting moment to a current moment, then carrying out remainder operation on the first time interval and one second to obtain a second time interval from the current moment to a last whole second moment, and finally, carrying out time delay according to the second time interval so as to output a second pulse signal and a computer time signal carrying year, month, day, hour, minute and second at the next whole second moment, so that microsecond-level time output of a computer can be realized. The invention further provides a computer microsecond-level time calibration system. A time interval measuring instrument measures the time interval error between the second pulse signal and the reference time signal generated by the external reference time source, and then the standard time signal generated by the external reference time source can be use