The invention discloses a labor saving use method for a bow. The method is achieved through a bow opening string, a push string, tensioners and a double-string releasing device. The double-string releasing device comprises a releasing trigger, a mechanical transmission mechanism and two releasing string hooks. The double-string releasing device can be suitable for a pulley bow provided with the bow opening string and the push string, the pulley bow is easy to open, balance adjustment on the pulling distance in the bow opening process of the bow opening string and the push string is achieved by pre-tensioning the bow opening string, the sport performance and the sport pleasure can be improved, popularity of the bow and arrow sport is improved, and implementation is easy.