Embodiments of the present invention relate to a signal order-preserving method and apparatus. When data of a request signal that comes from a corresponding first upstream device is written into a first first input first output (FIFO) memory, invalid data is written into a second FIFO memory corresponding to a second upstream device in a same clock cycle; and the data of the request signal is read from the first FIFO memory, the invalid data is read from the second FIFO memory, the invalid data is discarded, and the data of the request signal is conveyed to a downstream device. Through the signal order-preserving method and apparatus in the embodiments of the present invention, the coupling extent between devices on which there is an order-preserving requirement is reduced while signal order-preserving is achieved.