The invention relates to a partial discharge measurement apparatus and method using integral spectrophotometry. The apparatus includes an integrating sphere, which is used for providing a closed environment and built in with a discharge defect model and has an inner surface coated with a diffuse reflection coating for diffuse reflection of different types of optical signals generated by the discharge defect model uniformly for a plurality of times and outputting; a power supply module, which is arranged outside the integrating sphere, connected with the discharge defect model and used for providing power supplies of different parameters for the discharge defect model; an integrating sphere internal environment regulating component, which is connected with the integrating sphere and used for changing the gas environment in the integrating sphere, including the gas type, pressure, temperature and humidity; and a parameter detecting component, which is connected with the power supply module and used for obtaining an optical parameter, an environmental parameter and an electrical parameter of the integrating sphere and for processing and displaying the above parameters. Compared with the prior art, the apparatus and method of the invention have the advantages of effective signal collection, controllable discharge environment, high detection accuracy and so forth.