The invention discloses a waste-liquid zero-discharge processing apparatus and a waste-liquid processing method. The processing apparatus comprises waste-liquid conveying equipment, a pre-settlement pool, a buffer pool, atomization equipment, a solid-liquid-gas separation device and a dedusting device; a water conveying pipe of the waste-liquid conveying equipment is connected with the pre-settlement pool, the pre-settlement pool is connected with the buffer pool, and the buffer pool is connected with the atomization equipment via a water conveying pipe; and the atomization equipment is disposed at the inlet at the top of the solid-liquid-gas separation device, and the gas outlet of the solid-liquid-gas device is connected with the dedusting device via a pipe. The processing method comprises enabling wastewater to enter the buffer pool via the pre-settlement pool, atomizing through the atomization equipment, then sending to the top inlet of the solid-liquid-gas separation device; introducing a high-temperature gas flow via the top inlet, so as to vapor water in atomized small liquid drops and obtain impurity particles, and agglomerating and forming relatively large agglomerated inclusions through high-intensity sound waste emitted by the sounding device, and enabling the agglomerated inclusions to become a stalling state and accelerate to sink through the static-pressure capacity expanding area, and discharging. Through the unique apparatus design, wastewater is furthered purified, and the purpose of zero discharge is finally reached.