The present invention discloses a two-dimensional absolute displacement 
encoder, which comprises a light 
path system and an FPGA 
signal processing system. The light 
path system comprises a parallel 
light source, a two-dimensional absolute encoding code channel, an 
imaging lens group, an aperture diaphragm and an 
image sensor. The two-dimensional absolute encoding code channel is placed on a to-be-measured plane, and is composed of code elements the same in size and encoded in the pseudo 
random coding mode, wherein the code elements are capable of reflecting the light or not capable of reflecting the light. The FPGA 
signal processing system mainly conducts the FPGA realization for the configuration of the 
image sensor, the reading of the image information, the median filtering and binarization treatment of images, the image cache, the code identification, the decoding 
algorithm and the like. Meanwhile, the FPGA 
signal processing system realizes the output of two-dimensional absolute position measurement values. The two-dimensional absolute displacement 
encoder has the advantages of simple structure and strong real-time property. The two-dimensional absolute displacement 
encoder can quickly decode and output a two-dimensional absolute position measurement value. The two-dimensional absolute displacement encoder can be widely applied to the 
absolute positioning and the precision measurement of a two-dimensional 
workbench and has a good practical application prospect.