The invention discloses a solar petroleum heating device capable of reducing petroleum viscosity. The solar petroleum heating device comprises a petroleum pipeline. A mounting groove is formed in the top of the outer side of the petroleum pipeline. Two first containing grooves are formed in the inner wall of the bottom of the mounting groove and are arranged horizontally. Push rod motors are fixedly mounted in the two first containing grooves. A connecting rod is welded to an output shaft of each push rod motor. A communicating hole is formed in the top of the side, extending into the mounting groove, of each connecting rod, and a rotary shaft is fixedly mounted in each communicating hole. The solar petroleum heating device is economical and practical; a solar panel can be driven by the push rod motors to adjust the angle, and the efficiency that the solar panel absorbs solar energy is greatly increased; a drive motor and a dual-shaft stepping motor are utilized for driving stirring rods, petroleum in the petroleum pipeline can be stirred, the petroleum can have flowability, and then heating pipes and heat radiators are utilized for heating the petroleum; and the solar petroleum heating device is used for reducing the petroleum viscosity and is convenient to use and simple in operation.