The invention discloses a method for hydrocracking polycyclic aromatic hydrocarbons in a super gravity reactor. The method comprises the following steps: 1, selecting the super gravity reactor comprising a motor, a main shaft, a rotor, a shell, a rotating disc and a charging chamber, wherein an ultrasonic probe is arranged in the charging chamber; 2, switching on the ultrasonic probe in the charging chamber, and pre-mixing gas and liquid phase reaction raw materials to make hydrogen dispersed into a lot of nano-micro bubbles and the hydrogen solubility reach a saturation value in order to forma gas and liquid mixture; and carrying a reaction on the gas and liquid mixture in the super gravity reactor. The special reactor has the advantages: the bubbles exist in the liquid phase for a longtime; the gas and liquid transfer efficiency is high; the pressure of hydrogen in the reactor can be properly reduced, so the safety is improved; the reactor has no need to be serially connected withother large gas and liquid pre-mixing devices, so the device investment is reduced; and the conversion rate of the polycyclic aromatic hydrocarbons is increased by 5% or more, and the product yield isincreased by 6% or more.