The invention discloses a 100/Gigabit adaptive optical Ethernet physical layer realization circuit, comprising an optical module, a network speed automatic identification module and a receiving process physical layer module. The network speed automatic identification module is used for determining the current optical communication rate information. A physical layer module of the receiving processcomprises a data stream multiple sampling module and a data stream restoration module, the data stream multi-sampling module is used for generating eight sampling clocks with the same frequency and the phase difference of the sampling edges is 45 degrees in turn for sampling to obtain a sampling data set, and the data stream restoration module is used for generating a restoration point data set according to the sampling data set. The invention samples the serial receiving data obtained by the receiving end of the receiving optical module through eight sampling clocks with a phase difference of45 degrees, by adaptively identifying the sampling edge in the middle of the duration period of the bit of the serial received data, the accurate bit value of the serial received data is obtained, which improves the sampling accuracy and data transmission quality.