Appropriate fertilizer management was put forward in order to improve the utilization rate of potassium fertilizer，andthe effects of different fertilizer combined with nano carbon fertilizer synergist on potato growth，yield，quality and utilizationrate of potassium fertilizer were studied by different fertilization treatments. The results showed that the plant height and main stem perimeter of nano carbon combined with 70% conventional fertilization(C+0.7NPK)were higher than nano carbon combined with coventional fertilization(C+NPK)，and the plant height and main stem perimeter of nano carbon combined with 70% potassium conventional fertilization(C+0.7K)were higher than CK，and the relative chlorophyll content of C+0.7NPK was higher than other treatments. The yield of C+0.7K was the highest，followed by that with C+0.7NPK. The yield of C+0.7K was only 0.24% higher than C+0.7NPK，C+NPK had lower yields than NPK. Compared with other treatments，the effect of C+0.7NPK and C+0.7K on reducing the crude protein content of potato was better，and the addition of nano carbon fertilizer synergist improved the starch content. The K fertilizer use efficiency of C+0.7NPK and C+0.7K was 68.07% and 39.74%，respectively，and was significantly higher than NPK.In summary，the fertilizer reduction of 30% and the addition of nano carbon fertilizer synergist could ensure the yield and quality，while the K fertilizer use efficiency is better than other fertilization measures.