The utility model discloses an overload protecting and weighing protector of a construction lifter, which comprises tension sensors and ring plate type tension sensors arranged on the construction lifter; two rings of the ring plate type tension sensors are respectively connected with a drive plate pin roll of the construction lifter and a suspension cage pin roll; signal output terminals of the ring plate type tension sensors are connected with the input end of a signal amplifier; the signal output end of the signal amplifier is connected with the input end of an A/D converter; the signal output end of the A/D converter is connected with the signal input end of a 16-digit singlechip processor; and two signal output ends of the 16-digit singlechip are respectively connected with a relay, a display and an alarm of an electrical control system for controlling the lifter and the signal input end output by weight pulse. The utility model can accurately weigh the load in the suspension cage of the lifter, has high reliability, can be simply and repeatedly arranged, acquires an effective signal for a control circuit of the lifter and can be widely used for overload protection of various construction lifters.