The horizontal rectangular guide CNC lathe is a horizontal rectangular guide CNC lathe with double guide rails, a maximum rotation diameter of the bed up to 1000mm, and a linear axis stroke up to 2000mm. After searching, there are four industry standards in the field of accuracy inspection of horizontal rectangular guide rail CNC lathes, but these standards cannot meet the accuracy inspection needs of products. This standard specifies the structural type, general requirements, geometric accuracy, position accuracy and product working accuracy of horizontal rectangular guide rail CNC lathes. It is suitable for horizontal rectangular guide CNC lathes with a maximum bed rotation diameter of 1000mm and a linear axis stroke of 2000mm.