in connection with the drawings and embodiments in the following as shown in fig2 a system structure adopted by an absolute signal consistency correction method for an absolute grating scale includes a light source 1 a collimating lens 2 a grating scale 3 on which absolute codes are engraved a photodiode array 4 an amplifying and sampling holding circuit array 5 a bias correction circuit 6 a gain correction circuit 7 a consistency correction structure 8 a storage 9 and a host computer 10 wherein the consistency correction structure 8 includes the bias correction circuit 6 and the gain correction circuit 7 the photodiode array 4 the amplifying and sampling holding circuit array 5 the bias correction circuit 6 the gain correction circuit 7 and the storage 9 are integrated on one silicon slice the system structure adopts a working principle that firstly a system is powered on and the host computer 10 transmits initial correction data vectors a 1 1 n of the gain correction circuit 7 and initial correction data vectors b 1 1 n of the bias correction circuit 6 to the storage 9 the light source 1 can emit light with corresponding intensities by regulating bias currents of the light source 1 the light passes through the.