Disclosed are a code disc and an encoder. The code disc includes a code channel component obtained by coding according to a set coding mode, and a fixed grating corresponding to the code channel component; the coding mode is configured to increase a width of an absolute window of the code channel component. By the solution of the disclosure, problems that the absolute signal window becomes narrower as the number of reticles of the incremental code channel increases and accordingly the reliability of the encoder is reduced are solved, thereby improving the reliability of the encoder.