Abstract: The effect of particle size of cooked mashed potato on the appearance color, cooking quality and texture quality of potato noodles was studied, and the particle size was controled by grinding time and intensity. The data was used to support the production of potato noodle. The results showed that the particle size of cooked mashed potato gradually decreased with the increase of the grinding strength and time. The potato flour particles had obvious bimodal particle size distribution, the proportion of small particles was relatively small, the proportion of large particles was relatively high. Observed under scanning electron microscope (SEM), cooked mashed potato had a flaky structure. With the decrease of particle size, the thickness of the sheet was continuously thinner and the size of the sheet was becoming smaller. With the decrease of particle size, L^* value and viscosity of potato noodle decreased, a^* value and b^* value of potato noodle increased. The L^*, a^*, and b^* values of noodle A had significant differences (p<0.05) with the corresponding L^*, a^*, and b^* values of noodles B, C, D, and wheat noodles, the L^* values of noodles B, C, and D had no significant difference (p>0.05). As the particle size decrease, the cooking loss increased from 9.38% to 10.16%. There was no significant difference in the breaking distance of potato noodles with different particle size (p>0.05), and the breaking distance of potato noodles was significantly higher than that of wheat flour noodles (p<0.05).Shear hardness and viscosity of potato noodle and were significantly smaller than wheat flour noodles (p<0.05). In general, the particle size of mashed potato had influence on the quality of its noodles, the potato noodle with 130 μm of particle size cooked mashed potato flour had the best quality.