The invention discloses a positive-pressure and explosionproof power generator. The positive-pressure and explosionproof power generator comprises a power generator body, a positive-pressure purging pipeline, a wiring cabinet, a neutral point cabinet, an excitation system and a positive-pressure purging device and is characterized in that the power generator body comprise a stator, a rotor and anair-air cooler and employs a light box-type structure of an end cover-type bearing, an integral end cover and a steel plate welding engine base, the air-air cooler is placed at the top of the power generator body and employs a pipeline forced ventilation air-air-cooling system, at a steam end of the power generator, a power generator body positive-pressure sealing space is formed by the light box-type structure and the air-air cooler, and at an excitation end of the power generator, an excitation magnetic system positive-pressure sealing space is formed by an excitation machine support and anexcitation machine outer cover. By the structure, the explosionproof performance of the power generator can be effectively improved; and moreover, the positive-pressure and explosionproof power generator is simple to operate and maintain and convenient to install and connect and is good in air tightness, and long-time and safe running of the power generator set in a flammable and combustible environment can be achieved.