The present invention provides a wax oil hydrotreating method comprising the following steps: hydrogen gas is sent into a wax oil raw material by pores with the average pore size in nanometer-size to obtain hydrogen-containing wax oil; and the hydrogen-containing wax oil is fed into a tubular reactor for contacting with a hydrogenation catalyst filled in the tubular reactor under conditions of liquid-phase hydrogenation processing. Even hydrogen oil ratio is lower, and space velocity is higher, sulfur and nitrogen in the wax oil can be effectively removed, part of aromatics are saturated, hydrogen-carbon atom ratio of the wax oil can be improved, and a high-quality catalytic cracker raw material can be obtained.