Power-on timing sequence control system and method of PCIE (Peripheral Component Interface Express) board card

The invention provides a power-on timing sequence control system and method of a PCIE (Peripheral Component Interface Express) board card. The system comprises a self-adaptation circuit, a delaying circuit, an overheating protection unit and a recovering circuit. The method is used for carrying out delaying control on other direct-current power supplies through a direct-current power supply 1 (P1). According to the power-on timing sequence control system and method of the PCIE board card, the board card can be powered on in a shorter time T and each power supply needed by a sub-card can be powered on according to a certain sequence; a sub-card support slot and a self-adaptation manner of supplying power by double power supplies of external power supplies are adopted to support a heat resetting function; and after overheating protection is carried out and the temperature of the sub-card is reduced to a safe range, the sub-card automatically recovers the normal work and a main board does not need to be started again.