A method for improving tensile strength of zirconium and zirconium alloy relates to a preparing method for the zirconium and zirconium alloy, being used in the preparing process of the zirconium and zirconium alloy for nuclear power, metallurgy, petrochemical industry and other fields. The invention is characterized in that the zirconium and zirconium alloys are added with zirconium dioxide during smelting, and oxygen content in the zirconium and zirconium alloys is controlled to be 0.08% to 0.3%. In the method of the invention, embarking on controlling oxygen content in the zirconium and zirconium alloy, and adding zirconium dioxide during ingot melting of the zirconium and zirconium alloy, the oxygen content in the zirconium and zirconium alloy is controlled by controlling addition amount of the zirconium dioxide; the produced zirconium ingot has uniform oxygen distribution and no metallurgical defects, such as impurities and the like. The present invention has obvious advantages, such as simple operation, accurate control, stability and the like, solves the problem of adding oxygen in zirconium ingot smelting process, and effectively improves conventional performance such as tensile strength and the like to meet the requirement of zirconium materials in industry without affecting the performance of zirconium materials such as corrosion resistance.