A preparation method of NiTiNbCo wide hysteresis memory alloy is disclosed, which relates to a preparation method of the NiTiNbCo memory alloy and solves the problems that the NiTiNbCo memory alloy prepared by the prior art has inferior resilience, low yield strength and unsatisfactory safety performance as a connection fastener. The method comprises the following steps: 1. raw materials are mixed, turned over, agitated and smelted to prepare ingot casting; 2. the ingot casting is remelted to manufacture a bar which is successively cooled; and 3. the cooled bar is polished, washed and put in a quartz tube for homogenization treatment, hardening and annealing are then performed, afterwards, the bar is hot-rolled to a rolled plate. The NiTiNbCo wide hysteresis memory alloy obtained by the invention has the advantages of high resilience, high yield strength and safe and reliable connection. The preparation method of the invention has simple process and low cost.