The invention relates to a preparation method of a covalence organic framework material for detecting trace water in an organic solvent. The preparation method adopts a solvothermal method. The preparation method comprises the following steps: mixing 1,4-dihydroxy terephthalaldehyde, 2,4,6-tri(4-amino phenyl)-1,3,5-triazine, acetic acid, o-dichlorobenzene or mesitylene, and N,N-diethylacetamide, and ultrasonically uniformly dispersing; transferring a tube with a reaction solution to an environment with the temperature of 120 DEG C to react for 3d; and centrifugally separating obtained red solids, and alternately cleaning the separated solids by using tetrahydrofuran and dichloromethane, and then drying to obtain the needed covalence organic framework material. The preparation method has the advantages that the covalence organic framework material prepared by the method is high in crystallization degree, good in heat stability and chemical stability, stable in fluorescence performance, high in sensitivity to the trace water in the organic solvent, and can be reused for multiple times, so that an effective way is provided for detecting the trace water.