The utility model relates to a laborsaving lever mechanism, it is one -level lever structure to have solved the current tight drive arrangement of clamp, laborsaving effect is general, it needs great power frequently to hold to close down, the harder defect of in -service use, it has the afterburning handle of second grade to articulate on the support, the afterburning handle of second grade is articulated mutually with the afterburning handle of one -level, three articulated position has at least one to articulate for sliding, the afterburning handle of second grade contacts with afterburning handle articulated tip outside limit of one -level and afterburning piece side, when the afterburning handle of one -level rotates the thrust augmentation, between afterburning two pin joints of handle of second grade between distance increase or afterburning two pin joints of handle of one -level the distance reduce or the support on between two pin joints distance reduce. The afterburning handle of one -level will be done all can to transmit and become second grade lever structure, afterburning handle of second grade and afterburning piece contact and the afterburning piece of promotion for the afterburning petioliform of second grade to the drive push rod gos forward, becomes the secondary from the afterburning handle of one -level to the afterburning petioliform of second grade and enlargies, and it is more convenient to exert all one's strength.