The invention discloses a pollution-free leather manufacturing technology. The pollution-free leather manufacturing technology includes the steps of leather finishing, leather soaking, preliminary tanning, secondary tanning, repeated secondary tanning, tanning finishing, dye-fixing agent adding, semi-finished product manufacturing, softening and finished product manufacturing. In the leather soaking step, the water volume for soaking naked leather accounts for 30% to 50% of the mass of the naked leather, and soaking time ranges from 20 min to 30 min. In addition, the ratios of solutions added to a drum are adjusted in proportion in the steps, and the rotation time of the drum is controlled. Thus, by the adoption of the pollution-free leather manufacturing technology, the use ratio of water to auxiliary materials is strictly controlled, all liquid is completely absorbed by leather, no sewage is drained, and no pollution is generated to the environment.