Chronic kidney disease has attracted great attention as a public health disease and is mainly caused by the retention of uremic toxins in the body. Urea is a kind of representative toxin with high solubility and cannot be removed easily; in fact, no suitable absorbers have been found to remove urea by physical adsorption. Herein, we prepare urease-immobilized magnetic graphene oxide as a recyclable nanocatalyst for effective urea removal in blood purification, which shows great removal ability toward urea (2194 +/- 110 mg/g). The clearance ratio is over 80% even for a high concentration urea solution of 80 mg/mL, and it is 77% for collected dialysate from a clinic. The nanocatalyst exhibits good reusability and storage stability. Furthermore, a series of blood-related tests indicate that the prepared nanocatalyst has good blood compatibility. Thus, the urease-immobilized recyclable nanocatalyst has great potential for effective and safe urea removal in blood purification.