The moisture-absorbing air respirator DAB-90-90 is mainly used to absorb moisture and filter the air in the fuel tank. Its working principle is that when the air passes through the desiccant, the moisture is absorbed. After passing through the desiccant, the solid particles in the air are removed when the air filter element passes through the desiccant, which can effectively prevent the liquid level from rising and falling and thermal expansion and contraction. The resulting pressure difference causes moisture and solid particles to invade the oil tank, effectively improving the working performance and reliability of the hydraulic system, and extending the service life of the oil and equipment.