An adaptation method between PCIE and SPI realized based on FPGA, comprising following steps: S01: a PCIE equipment sends PCIE information to a mapping module through a PCIE module; S02: the mapping module extracts SPI information from the PCIE information and transmits the SPI information to a SPI equipment through an SPI module; all of the PCIE module, the mapping module and the SPI module are located on a FPGA chip; S03: the SPI equipment performs a read/write operation according to the SPI information, and feeds back SPI operation information subjected to the read/write operation to the mapping module; S04: the mapping module modifies PCIE information according to the SPI operation information to obtain PCIE feedback information; S05: the PCIE equipment reads the PCIE feedback information through the PCIE module. The present invention provides a conversion adapter and a method between PCIE and SPI realized based on FPGA to realize conversion for a PCI interface and a SPI interface, so as to perform a read/write operation of an AD chip with the SPI interface or a DA chip with the SPI interface, which has universal applicability.