The utility model relates to a rotating speed and aperture dual-adjustment device of a variable fertilizer applicator fertilizer ejecting shaft. The rotating speed and aperture dual-adjustment device comprises a rack, a rotating speed adjusting mechanism, an aperture adjusting mechanism and fertilizer ejecting devices. The rotating speed and aperture dual-adjustment device is characterized in that the rotating speed adjusting mechanism is arranged on the right side of the rack, the aperture adjusting mechanism is arranged on the left side of the rack, and the fertilizer ejecting devices are evenly distributed between the rotating speed adjusting mechanism and the aperture adjusting mechanism according to the specific field crop planting line spacing and the variable fertilizer applicator width. The rotating speed adjusting mechanism is composed of a rotating speed motor, a rotating speed motor base, a rotating speed sleeve, a rotating speed coupler, a supporting bearing, a rotating speed connecting piece and a spline. The aperture adjusting mechanism is composed of an aperture motor, an aperture motor base, an aperture sleeve, an aperture coupler, an aperture connecting piece and a rotating bearing. Each fertilizer ejecting device is composed of a fertilizer ejecting box, a groove pulley, a fertilizer ejecting blocking shaft, a clamp holder and a servo baffle. According to the rotating speed and aperture dual-adjustment device, the rotating speed and the aperture of the main fertilizer ejecting shaft can be adjusted at the same time, the working efficiency is improved, and the influence of fertilizer ejecting pulsatility on fertilizer application uniformity in the fertilizer application process is reduced.