This paper presents a design of 10Gb/s BCH decoder which is compatible with the protocol of G.975 and can be applied in optical fiber communication. The main blocks of this decoder include syndrome calculator, key-equation solver, Chien search and error correction. In order to achieve high speed, 8-bit parallel syndrome calculator and Chien search block are adopted. By sharing the key-equation solver, the numb er of key-equation solver is reduced and the hardware resources are saved. This decoder has been implemented in Virtex-5 FPGA and the verification results show that the decoder can work properly under the clock of 166MHz and the data rate can be up to 10Gb/s.