1. A system for dynamically adjusting operational environment, applicable to a computer cluster comprising: a plurality of operational nodes, each installing a first operational system and a second operational system; a control node, connected with said plurality of operational nodes, respectively, assigning at least a first-type task contained in an operational task to at least an operational node running said first operational system and at least a second-type task to at least an operational node running said second operational system, or controlling at least an operational node to restart for altering said first operational system or said second operational system running in said operational node; and a storage node, connected with said plurality of operational nodes, respectively, storing a plurality of operational results produced by said plurality of operational nodes after operating said plurality of first-type tasks and said plurality. of second-type tasks, respectively.