The invention discloses a filtering recovery device for magnetic material processing waste liquor and a filtering recovery method therefor. The device comprises a filtering barrel, a liquor feeding funnel, a liquor feeding valve, a partition plate, filtering assemblies, an electromagnet, conveying assemblies, a separating mechanism, a deposition tank, detecting assemblies and a controller. Each filtering assembly comprises a filter screen and a telescopic member, and each conveying assembly comprises a slide plate I, a baffle and a driving member. The detecting assemblies are used for detecting accumulation volume of wastes on each filter screen and adsorption capacity of magnetic wastes in each filtering space. The controller is used for driving corresponding telescopic members to retreatwhen the accumulation volume exceeds preset accumulation volume so as to increase degree of inclination of the filter screens; and when the adsorption capacity exceeds preset accumulation volume, a liquid outlet is closed firstly, then, a discharging opening is closed, a knockout through hole is opened, and finally, the electromagnet is shut off. According to the device and the method, the recycling rate of the magnetic material processing waste liquor can be increased, the cleaning of the waste liquor is facilitated, and environmental pollution caused by direct discharge of the waste liquoris avoided.