The invention discloses a system and method for recycling and supplying mortar to multi-wire cutting machines. The system comprises a finished product mortar storage tank, a main supply pipeline, an auxiliary reflowing pipeline, a branch supply pipeline, a waste liquid back-pumping main pipeline, a waste liquid back-pumping branch pipeline, a waste liquid recycling tank, a mortar separation and purification device, a silicon carbide dense mortar storage tank, a recycled liquid storage tank, a silicon carbide dense mortar pumping pipeline, a recycled liquid pumping pipeline, a cutting liquid supplementing pipeline and a silicon carbide micropowder supplementing pipeline. The method comprises the following steps of: firstly, supplying finished product mortar: reflowing the finished product cutting mortar before the mortar is supplied to the multi-wire cutting machines, supplying the finished product cutting mortar, completing the supplying of the mortar, and then continuously reflowing the finished product cutting mortar; secondly, recycling waste mortar; and thirdly, starting a stirrer of a mortar recycling device, separating and purifying the waste mortar, compounding and recycling the finished product cutting mortar. The system is reasonably designed, simply and conveniently operated, can simultaneously supply the mortar to a plurality of cutting machines without retaining the mortar in each pipeline.