The invention discloses a test method for calibrating detection results of different ultraviolet imaging instruments, which comprises the steps of taking the gain as a variable, testing a standard test object by adopting two ultraviolet imaging instruments under different gains, and acquiring two groups of test results; comparing the two groups of test results, and determining the corresponding gains when the two ultraviolet imaging instruments acquire equal or similar test results, namely the equivalent gains; and taking one group of test results of one ultraviolet imaging instrument as a standard, and comparing a test result of the other ultraviolet image instrument for a practical test object under a second gain value with a test result of the ultraviolet imaging instrument for the standard test object under a first gain value, wherein the first gain value and the second gain value are equivalent gains. After calibration is carried out through the test method disclosed by the invention, detection results of different ultraviolet imaging instruments can be compared so as to accurately determine the discharge severity and the insulation performance of electric power insulation equipment.