The invention discloses a lead-zinc slag waste heat recovery method and relates to the field of lead-zinc slag treatment in the non-ferrous metallurgical industry. The lead-zinc slag waste heat recovery method comprises the following steps of S1, preparing a lead-zinc slag waste heat recovery system; S2, continuously conveying solid lead-zinc slags to the inlet end of a conveying machine through adistributor; S3, controlling liquid lead-zinc slags to flow onto the conveying machine from a fuming furnace; S4, mixing upper layer solid lead-zinc slags and lower layer solid lead-zinc slags; S5, starting an exhaust fan, enabling air to flow into an exhaust fan cover below a conveyor belt of the conveying machine from the upper side of the conveyor belt of the conveying machine, and enabling hot air generated by heat exchange to flow into a waste heat recovery unit for recovery and utilization; and S6, enabling the solid lead-zinc slags to flow to a slag separation mechanism from the outletend of the conveying machine, wherein a part of the solid lead-zinc slags in the slag separation mechanism returns to the distributor, and the other part of the solid lead-zinc slags is discharged into a material field. The invention aims at overcoming the defects of shorter service life of the existing lead-zinc slag heat recovery device and provides the lead-zinc slag waste heat recovery methodto prolong the service life of the device.