The present invention provides an optical power measuring apparatus capable of monitoring the status, such as cleanness, of an optical fiber contact end face. The disclosed optical power measuring apparatus includes a microscope camera module, an illuminating module, an optical element, an optical power detection unit, a display unit and a central processing unit. The present invention may switch between optical fiber contact end status monitoring and optical power measurement. The apparatus can simplify the complicated steps for an optical fiber to insert to and pull from an optical microscope and then insert to an optical power meter. It can help a user to measure the correct optical power rapidly.