The invention discloses a method for making a silicon-on-insulator (SOI) chip, which comprises the following steps: S1, forming a first oxide layer with a dielectric isolation function on the surfaceof a poly-silicon substrate by thermal oxidation growth; S2, applying photoresist to the first oxide layer, and forming a through hole through exposing and etching; S3, forming a first poly-silicon layer on the surface of the first oxide layer through the through hole by selective epitaxial growth; S4, making silicon react with an oxidant at high temperature to form a second oxide layer on the first poly-silicon layer by thermal growth; S5, forming a second poly-silicon layer on the surface of the second oxide layer by selective epitaxial growth; and S6, implanting ions into an area, near thesecond oxide layer, in the second poly-silicon layer to form a metal impurity adsorption layer. The radiation resistance of SOI devices can be improved, and moreover, the influence of free metal impurities on the circuit and electronic components is avoided, and it is ensured that there are no white spots in the imaging of a CMOS image sensor with the SOI structure.