A method of testing a blocking ability of a photoresist blocking layer for ion implantation, comprising: forming a photoresist blocking layer (S1) on a substrate; measuring a first thickness (S2) of the photoresist blocking layer at an arbitrary position on the substrate, the first thickness being a thickness of the photoresist blocking layer; implanting a predetermined amount of ions (S3) into the photoresist blocking layer; measuring a second thickness (S4) of the photoresist blocking layer at the arbitrary position, the second thickness being a thickness of a hardened portion in the photoresist blocking layer; and determining a blocking ability (S5) of the photoresist blocking layer with the first thickness for ion implantation according to the second thickness. This method does not need to use a testing silicon slice during the process of testing the blocking ability of a photoresist blocking layer for ion implantation, and thus can reduce required costs during the testing process.