The functionalization of saccharides are one of the attractive researches in the field of drug development and biopharmaceuticals. In addition, PEG (polyethyleneglycol) is a polymeric compound with excellent solubility in water and biosafety, which has been utilized in various applications such as drug delivery, tissue engineering, and biochemical probes. In this work, we present a photoredox catalyzed decarboxylative vinylation of PEGylated sugar and alkynes. PEGylated sugars can generate alkyl radicals through photocatalyzed decarboxylation, which can then add to alkynes to couple PEGylated sugar and alkyne in the presence of a copper co-catalyst. The developed method achieved high E-selectivity in vinylation and tolerated a variety of functional groups under mild reaction conditions. This novel approach shows promise as an innovative transformation process for the synthesis of drugs and biochemicals, and is expected to provide new opportunities in the fields of organic chemistry and medicinal chemistry.