The present disclosure provides a method for determining an ore-forming environment of a porphyry deposit based on a tourmaline component, including the following steps: collecting a tourmaline-containing rock in the porphyry deposit to obtain a rock sample; performing pretreatment on the rock sample to obtain a treated sample; performing an in-situ tourmaline trace element test on the treated sample to obtain a test result; performing data processing and interpretation on the test result to obtain tourmaline trace element data; establishing a discrimination factor based on the tourmaline trace element data; and determining the ore-forming environment based on the discrimination factor. The present disclosure can quickly recognize a forming environment of a newly discovered porphyry deposit, thereby summarizing a rule and quickly giving guidance for a next prospecting direction.