Provided are a method of constructing a nucleic acid library, a method of determining a nucleic acid sequence of a nucleic acid sample, and a kit thereof. The method of constructing the nucleic acid library includes the following steps: subjecting a nucleic acid sample to a DOP-PCR amplification, to obtain a first PCR amplification product; subjecting the first PCR amplification product to a second PCR amplification using a DOP-Amp primer, to obtain a second PCR amplification product; and subjecting the second PCR amplification product to an adaptor-ligation PCR, to obtain a third PCR amplification product, wherein the third PCR amplification product constitutes the nucleic acid library.