Abstract: An encoder module with a sliding assembly comprises a cover, a disk, a reading head, a bottom plate, and a sliding unit; wherein in assembly, the disk is installed at an upper front side of the bottom plate; the reading head is installed upon a front side of the sliding unit; the sliding unit is pushed into a lower hole of the bottom plate so that a front end of the sliding unit exposes from the lower hole of the bottom plate; in that the reading head serves to read signals from the disk; finally the cover covers upon an outer side of the bottom plate, the sliding unit and the reading head so as to form as an encoder module with a sliding assembly.