The invention relates to a method for building a secondary air inlet of a heat recovery coke oven, which comprises the following steps of: 1, building an air inlet bottom; 2, building masonries at twosides of the air inlet to form a long groove body; 3, placing a mortar vibrator in the long groove body, wherein the mortar vibrator comprises a hollow rectangular structure consisting of four angledies, the adjacent edges between the angle dies are connected through the elastic pieces, a vibration mechanism is arranged in the rectangular structure, the appearance structure of the vibration mechanism is matched with the space of the hollow rectangular structure, the vibration mechanism is arranged in the space of the hollow rectangular structure, and the hollow rectangular structure is expanded and matched with the cross section size of the air inlet, so that the air inlet can be easily filled to prevent the masonry mortar from overflowing; 4, building an air inlet cover plate brick at the upper end of the long groove body, and discharging the air of the slurry through the mortar vibrator during building, so that the built mortar is full and meets the elevation requirement simultaneously. According to the method for building a secondary air inlet of a heat recovery coke oven, the mold is adopted to fill the air inlet, so that the mortar is prevented from overflowing, and when thecover plate brick of the air inlet is built, the mortar is full and the mortar is free from omission and bubbles.