Abstract: The application of 2-nitro-resorcinol was introduced.the impact of the use of orthogonal reaction method to change the five factors: ① the amount of concentrated nitrate acid ②the amount of acetic acid ③sulfonation time ④nitrification time ⑤the amount of urea , The optimization of process for preparation 2-nitro-resorcinol was study 5.5g Resorcinol was sulfonated by 25ml H2SO4 and nitrated by mixture acid (5mlHNO3,1.5ml H2SO4,3mlC2H5OH, 0.5g silica gel) for 3.5h at 5~l0℃ and then distilled by water vapour to give 3.21g 2-nitroresrcinol with total yield of 41.39%.