The invention discloses a trunk whitewashing machine, relates to the field of agricultural machines, and solves the problems of low whitewashing efficiency and a poor effect of an existing whitewashing machine. The employed technical solution is that the trunk whitewashing machine comprises a frame; the lower side of the frame is provided with wheels; a storage battery and a power system are arranged in the frame; the frame is provided with a feed box and a pressure pump; a suction pipe of the pressure pump is located in the feed box; the frame is also provided with two crank arms; the crank arms are arranged on the frame through rollers; the rollers are connected with the power system; the upper end of each crank arm is connected with a vertical sliding bar; each vertical sliding bar canvertically move relative to the corresponding crank arm; a spray box is arranged at the lower ends of the vertical sliding bars; the spray box is connected with the pressure pump; the inner side of the spray box is provided with a spray pipe; the spray pipe comprises an outer pipe and an inner pipe; at least one end of the outer pipe is unenclosed; the inner pipe is arranged in the unenclosed end;the outer pipe and the inner pipe can relatively slide; and each of the inner side of the outer pipe and the inner side of the inner pipe is provided with spray nozzles. The trunk whitewashing machine is capable of whitewashing a trunk from all sides, thereby increasing whitewashing efficiency and guaranteeing the whitewashing effect.