A magnetic auxiliary mechanism for a pivoted tool is disclosed. When an adjustable magnetic member therein is set in a released state, a repelling force generated between the adjustable member and a fixed magnetic member helps to push handles of the pivoted tool to move in opposite directions, thereby facilitating operation. When the adjustable magnetic member is set in a locked state, an attracting force generated between the adjustable and fixed magnetic members helps to hold the handles of the pivoted tool together. The magnetic auxiliary mechanism provides simple overall appearance, convenient operation and safe storage to the pivoted tool.