The invention relates to a whole soybean deep-fried dough stick and a processing method and device. The processing method comprises the following steps: boiling soaked soybeans in boiling water; mixing the boiled soybean and soybean boiling water according to a certain proportion, then feeding the mixture into a colloid mill and grinding the mixture into soybean milk; evenly mixing the soybean milk, flour, yeast powder and salt in a certain proportion to make dough; fermenting the dough, and stirring or kneading the fermented dough until the surface is smooth; dividing dough with the smooth surface into a predetermined number of raw dough sticks with a predetermined size; delivering the deep-fried dough sticks to a fryer, and executing frying at a preset oil temperature for a preset time.By adopting the processing method of the whole soybean deep-fried dough stick, the content of acrylamide in the deep-fried dough stick is reduced, the content of soybean protein, dietary fiber and lysine is remarkably improved, and oil is saved in the deep-frying process.