The invention discloses a rapid determination method of moisture content in HMX (cyclotetramethylenete-tranitramine) explosive. The rapid determination method comprises the following steps: preparing HMX explosive samples with different moisture content and determining the moisture content; collecting near infrared spectrums of the HMX explosive samples; pre-processing spectrum data and establishing a correction model by adopting a partial least squares (PLS) method; collecting a near infrared spectrum of a sample to be detected and calculating through the correction model to obtain the moisture content of the sample to be detected. The method disclosed by the invention has the advantages that 1) the prepared sample is sealed by adopting a plastic bag in a sample preparation process aiming at overcoming the difficulties that the moisture in the HMX samples is easy to evaporate in a testing process, the stability of the samples is poor and result errors are great; 2) the plurality of same samples are subjected to near infrared spectrum scanning to obtain an average spectrum, so as to reduce the difference of the samples; 3) characteristic wave bands are selected by adopting a correlation coefficient method to carry out modeling. An established PLC regression model has high reliability and a good predication effect, and rapid, accurate and non-destructive inspection of the moisture content in the HMX explosive can be realized.