The present invention relates to the field of pharmaceutical chemistry. In particular, the present invention relates to a class of alkynyl pyridine prolyl hydroxylase inhibitors (I). The experiment shows that such a compound has a good activity of inhibiting prolyl hydroxylase, and can enhance the generation and secretion of erythropoietin in cell or animal models, and thus can promote the generation of red cells, and can be used for the treatment or prevention of anemia, such as the chronic kidney disease anemia, and ischemic diseases, such as ischemic strokes, myocardial ischemia and other related diseases. The present invention also discloses a method for preparing such a compound.