The invention provides a Lyapunov optimization-based multi-server mobile edge computing unloading method and device, and the method comprises: building a task cache queue for a task generated by eachmobile device, and building a virtual task cache queue for a task which needs to be unloaded and is not processed by each mobile device; establishing a terminal power consumption model, a bandwidth model and a QoE model; collecting task cache queue information and virtual cache queue information of the mobile device and the bandwidth condition of the server at each preset time slice; constructinga Lyapunov drift and penalty function according to the collected information; and based on Lyapunov drift and a penalty function, a calculation unloading decision in the current time slice is solved.The technical effects of calculating and unloading based on the multi-server MEC, effectively reducing the task completion time and reducing the energy consumption of the mobile device are achieved.