The present invention provides a preparing method of ortho-nitrobenzonitrile series compound, wherein, R1 and R3 are simultaneously or respectively as hydrogen, C1-C6 hydrocarbyl, C1-C3 halohydrocarbon, C1-C3 sulfenyl, C1-C3 sulfonyl, fluorine, fluorine, chlorine, bromium, nitro, R2 and R4 are simultaneously or respectively as hydrogen, C1-C6 alkoxyl, characterized in that, the ortho-nitrobenzonitrile series compound can be reacted to prepare by the compound and the cyanide of general formula (II) under the action of the catalyst nickelous bromide; wherein, the definitions of the R1-R4 groups in the general formula (II) are the same as the general formula (I), X is as or fluorine. The method adopts the new catalyst nickelous bromide and has characteristics of high reaction conversion rate and selectivity and short reaction time, and is easy for the industrial production.