The self-propelled crane is used to lift the beam and plate transported to the bridge hole directly to the installation position. Applicable conditions: small and medium span precast beam and slab installation of flat anhydrous bridge hole. (1) A crane frame method: when hoisting, the crane is generally placed in the middle of the bridge hole to be hoisted, and if the lifting capacity is sufficient, the crane can also be placed behind the platform or on the bridge hole that has been hoisted. Hoisting should pay attention to the angle between the lifting rope and the beam surface should not be too small, generally 45 °- 60 °is appropriate, otherwise, a flat beam should be used. (2) the two cranes try to use each of the two cranes to hold one end of the beam and lift the beam synchronously to lift and erect the beam. When hoisting, according to the situation, the two cranes can be placed in one hole or two holes respectively. Hoisting should pay attention to the mutual cooperation of the two cranes, and there are full-time hoists under unified command.