The invention belongs to a production method of a light oil product, particularly an extraction process for light oil. The process includes a cylinder the top of which is fixedly connected to a motor.Front and rear sides in stirring plates are provided with cooling chambers communicating with the inner core of a hollow pipe. Each stirring plate, between the two cooling chambers, is provided withat least eight liquid outlets communicating the inside of the cylinder with the outer core of the hollow pipe, with the liquid outlets being arranged in an even diverging manner. The lower surface ofone end, of a rotating bar, far from the hollow pipe is fixedly connected to a round slide block. The lower end of the cylinder is provided with a swing block the upper surface of which is provided with a slide slot in which the round slide block slides. A first pneumatic cylinder is disposed at the right side of the swing block. A drive end of the first pneumatic cylinder is fixedly connected tothe swing block. Two chambers in the first pneumatic cylinder contain a cooling liquid and a catalyst respectively, and communicate with the inner core and outer core of the hollow pipe respectively through pipes.