An SOI substrate manufacturing method and an SOI substrate are provided, where the SOI substrate manufacturing method includes: forming a patterned etch-stop layer (130) in an oxide layer (120) of a first silicon substrate (110), bonding a surface, having the patterned etch-stop layer (130), of the first silicon substrate (110) with a surface of a second silicon substrate (210), and peeling off a part of the first silicon substrate (110) to form a patterned silicon on insulator SOI substrate (300). A problem in the prior art that when a heteroepitaxial layer is grown on a silicon layer of an SOI substrate, lattice mismatch and thermal mismatch occur between the silicon layer and the heteroepitaxial layer is resolved. A heteroepitaxial layer without threading dislocations can be formed on a silicon layer of an SOI substrate, and a rate of lattice mismatch between a silicon substrate and the heteroepitaxial layer is reduced to a great extent, so that usage performance and reliability of a photoelectric device are improved.