The invention discloses a method for improving sandy soil without tillage with straw in cooperation with biochar. The method comprises the steps that firstly, after corn is harvested, half of corn straw by mass is removed, the other half of the corn straw by mass is chopped into small sections with the length ranging from 4 cm to 6 cm to obtain corn straw fragments, small furrows with the depth being 5 cm are directly formed through a furrower for sowing wheat, and then the corn straw fragments and biochar with the carbon amount equal to that of the corn straw fragments are evenly spread; secondly, after wheat is harvested, half of wheat straw by mass is removed, the other half of the wheat straw by mass is chopped into small sections with the length ranging from 4 cm to 6 cm to obtain wheat straw fragments, the wheat straw fragments and biochar with the carbon amount equal to that of the wheat straw fragments are evenly spread, and corn is directly sown through a seeder; thirdly, the first step and the second step are repeated three times. According to the method for improving sandy soil without tillage with straw in cooperation with biochar, the total no-tillage mode is adopted, half full-dose straw and half biochar with the equal carbon amount are used for covering after seeding, and through improvement tests of six turns in three years, the physical and chemical structures of sandy soil are effectively improved, and the nutrient of sandy soil and the crop yield are increased.