A slop oil treating device, comprising: a pretreatment device, a solid-liquid separator, a demulsification nucleus-increasing treating device, a squeezing filter press, a three-phase separator, a buffer tank, a feeding pump, a circulating pump, a conveying pump, and an outputting pump; wherein, the feeding pump is connected to the pretreatment device, slop oil which comprises an emulsified oil-water mixture in an oil tank is delivered to the pretreatment device through the feeding pump for a pre-treatment; the pretreatment device is connected to the solid-liquid separator, the slop oil is subjected to a pre-heating at a temperature ranging from 90°C to 92°C in the pretreatment device, and conveyed to the solid-liquid separator for a first-stage separation; the squeezing filter press is connected to the solid-liquid separator and the emulsification nucleus-increasing treating device, respectively, the circulating pump is connected to the emulsification nucleus-increasing treating device and the pretreatment device, respectively, a solid residue after the first-stage separation enters the squeezing filter press for a solid-liquid squeezing; the squeezing filter press discharges a squeezed solid residue and conveys squeezed waste water to the demulsification nucleus-increasing treating device, and then the squeezed waste water is conveyed to the pretreatment device through the circulating pump; and the three-phase separator is connected to the conveying pump, the demulsification nucleus-increasing treating device and the buffer tank, respectively, the conveying pump is connected to the solid-liquid separator, the outputting pump is connected to the buffer tank, an oil and water mixture after the first-stage separation enters the three-phase separator for a second-stage high-speed centrifugal separation; an oil separated by the three-phase separator is conveyed to the buffer tank, and conveyed to a storage tank through the outputting pump, water separated by the three-phase separator is conveyed to a waste water treatment workshop for a processing, and an emulsion separated by the three-phase separator is conveyed to the demulsification nucleus-increasing treating device for a nucleus-increasing pretreatment, and then returned to the pretreatment device and the solid-liquid separator, characterized in that the solid-liquid separator is located downstream of and connected to the pretreatment device, the three-phase separator is located downstream of and connected to the solid-liquid separator, the demulsification nucleus-increasing treating device is located downstream of and connected to both the solid-liquid separator and the three-phase separator, and the squeezing filter press is connected between the solid-liquid separator and the demulsification nucleus-increasing treating device. the feeding pump is connected to the pretreatment device, slop oil which comprises an emulsified oil-water mixture in an oil tank is delivered to the pretreatment device through the feeding pump for a pre-treatment; the pretreatment device is connected to the solid-liquid separator, the slop oil is subjected to a pre-heating at a temperature ranging from 90°C to 92°C in the pretreatment device, and conveyed to the solid-liquid separator for a first-stage separation; the squeezing filter press is connected to the solid-liquid separator and the emulsification nucleus-increasing treating device, respectively, the circulating pump is connected to the emulsification nucleus-increasing treating device and the pretreatment device, respectively, a solid residue after the first-stage separation enters the squeezing filter press for a solid-liquid squeezing; the squeezing filter press discharges a squeezed solid residue and conveys squeezed waste water to the demulsification nucleus-increasing treating device, and then the squeezed waste water is conveyed to the pretreatment device through the circulating pump; and the three-phase separator is connected to the conveying pump, the demulsification nucleus-increasing treating device and the buffer tank, respectively, the conveying pump is connected to the solid-liquid separator, the outputting pump is connected to the buffer tank, an oil and water mixture after the first-stage separation enters the three-phase separator for a second-stage high-speed centrifugal separation; an oil separated by the three-phase separator is conveyed to the buffer tank, and conveyed to a storage tank through the outputting pump, water separated by the three-phase separator is conveyed to a waste water treatment workshop for a processing, and an emulsion separated by the three-phase separator is conveyed to the demulsification nucleus-increasing treating device for a nucleus-increasing pretreatment, and then returned to the pretreatment device and the solid-liquid separator, characterized in that the solid-liquid separator is located downstream of and connected to the pretreatment device, the three-phase separator is located downstream of and connected to the solid-liquid separator, the demulsification nucleus-increasing treating device is located downstream of and connected to both the solid-liquid separator and the three-phase separator, and the squeezing filter press is connected between the solid-liquid separator and the demulsification nucleus-increasing treating device.