The invention discloses a high-sensitivity Beidou satellite B1I signal capturing method. The defects in the prior art that the computation burden is huge, the processing speed is slow, and a local recurrence signal is generated repeatedly are overcome. The method comprises the following steps that firstly, a Beidou satellite B1I signal is input; secondly, grouping is carried out on data; thirdly, partitioning is carried out on the data; fourthly, a data block is modulated by adopting a NH code; fifthly, overlapping is carried out on the data block; sixthly, the local recurrence signal is generated; seventhly, Fourier transformation is carried out; eighthly, a correlation value is obtained; ninthly, a non-coherent integration value is obtained; tenthly, a local recurrence signal frequency is changed; eleventhly, it is judged that whether the cycle times are less than 10 times or not, if the cycle times are less than 10 times, the eighth step is executed, and if the cycle times are not less than 10 times, the twelfth step is executed; twelfthly, capturing and detecting are carried out. Compared with the prior art, the high-sensitivity Beidou satellite B1I signal capturing method has the advantages of being high in processing speed, and good in capturing performance.