The invention relates to a novel nucleoside protective group and a preparation thereof. Concretely, the invention provides a compound with a structure shown in a formula 1, wherein R1 is selected from C1-C6 alkyl or C6-C14 aryl, preferably C1-C4 alkyl or phenyl, such as methyl, ethyl or phenyl; R2 is selected from C1-C6 alkyl or C6-C14 aryl substituted C1-C6 alkyl, preferably C1-C4 alkyl or phenyl substituted C1-C4 alkyl, such as methyl, ethyl, benzyl or phenethyl; X is halogen, and preferably chlorine. In the acidic condition, compared with traditional 4,4'-dismethoxytriphenylmethyl nucleoside protective group, deprotection of the compound is easier.