The embodiment of the invention discloses a task scheduling method and device. According to the task scheduling method and device, tasks are completed effectively, and at the same time, the purpose of reducing power consumption is taken into account. The task scheduling method includes the steps: obtaining tasks to be processed, determining priorities of the tasks to be processed by the adoption of a list scheduling dependency algorithm, and ranking the tasks to be processed according to a priority sequence from high to low; according to an energy-saving scheduling dependency algorithm, determining priorities of virtual machines, and ranking the virtual machines according to a priority sequence from high to low, wherein the priorities of the virtual machines take the processing speeds of the virtual machines into account; according to the sequence of the tasks to be processed and the sequence of the virtual machines, sequentially obtaining execution time of the tasks to be processed in each virtual machine, determining virtual machines in which the execution time of the tasks to be processed is smaller than or equal to a threshold value, and using the determined virtual machines as alternative virtual machines; selecting one from the alternative virtual machines as a virtual machine corresponding to the tasks to be processed.