The invention relates to a crystal form of N,N-diethyl-2-hydroxy-2-phenylacetamide as well as preparation method and an application of crystal form. An X-ray powder diffraction pattern of the crystalform is shown in the specification, and has characteristic peak represented by 2theta diffraction angle: 7.526+ / -0.2 DEG, 10.539+ / -0.2 DEG, 13.020+ / -0.2 DEG, 15.221+ / -0.2 DEG, 16.344+ / -0.2 DEG, 17.977+ / -0.2 DEG, 18.567+ / -0.2 DEG, 19.514+ / -0.2 DEG, 21.065+ / -0.2 DEG, 22.661+ / -0.2 DEG, 23.660+ / -0.2 DEG, 25.348+ / -0.2 DEG, 25.886+ / -0.2 DEG, 26.321+ / -0.2 DEG, 27.033+ / -0.2 DEG, 29.309+ / -0.2 DEG, 30.188+ / -0.2 DEG, and 31.193+ / -0.2 DEG; the crystal form is prepared by taking mandelic acid as a raw material, a condensation reaction with cyclohexanone is carried out and then an aminolysis reaction with diethylamine is carried out, and the method has the advantages of few synthesis steps, no pollution of reactants, mild reaction conditions, simplicity in operation, purity up to 99.9% and less generated three wastes, and is suitable for industrial production. The crystal form can also be used for preparing low-alcohol mosquito repellent liquid, and the low-alcohol formula avoids the harm of high-concentration ethanol to the skin and is suitable for children and people with sensitive skin.