High temperature has already become a noticeable environmental factor for crop production, while plant pollen was the most sensitive organ to high temperature stress. In this paper, the cytological, physiological, and molecular biological studies on the high temperature stress on crop pollen were reviewed, aimed to provide ideas for maintaining high productive ability of crops under high temperature stress. The cytological effects of high temperature on crop pollen included the changes of arrangement patterns of rough endoplasmic reticulum in tapetum cells, the irregularity of vascular bundle sheath cells in connective tissue, and the reduction of vesicle production by dictyosomes of pollen tube, etc.; physiological effects involved the incapacity of timely recovery of Ca2+ homeostasis, the changes of growth regulators contents, and the slowing down of carbohydrate metabolism, etc.; and molecular biological effects manifested in the insufficient induction of heat shock proteins and the inhibition of other functional genes for pollen development, etc.