Automatic tightening means of lifting hook

The utility model relates to an automatic tightening means of lifting hook, including davit arm head and hook assembly, the inside of davit arm head be provided with arm head pulley group, hook assembly includes lifting hook, layer board and lifting hook wheelset, the davit arm head on be provided with fixation with steel wire portion, the lower part of davit arm head is provided with the layer board support, the bottom of layer board support is provided with bending plate no. 1, the top of layer board be provided with bending plate no. 2, fixation with steel wire portion include dog, check block grooves and semicircle wheel, check block grooves is the cavity structure that open side down, check block grooves's upper portion opening is greater than the lower part, check block grooves setsup on the upper portion of davit arm head, the dog setting is in check block grooves's inside, the quantity of semicircle wheel has two, the flat surface parallel setting of two semicircle wheels is in check block grooves's b