The invention relates to an on-site collection method of a 
karst cave water environment DNA sample, which comprises the following steps: 1, collecting water from a 
karst cave water environment DNA detection point by using a Bailer tube, and putting the collected 
water sample into a disposable plastic basin for later use; 2, preliminarily filtering the 
DNA water sample in the 
karst cave environment collected in the step 1, and removing large-particle impurities, 3, taking a disposable 
syringe, sucking the preliminarily filtered 
water sample, connecting the water sample to a membrane-replaceable 
needle type filter loaded with a 
glass fiber membrane, manually extruding the 
syringe at a 
constant speed to enable the water sample to pass through the membrane-replaceable 
needle type filter, and then discharging the water sample, putting the replaced filter membrane into a centrifugal tube filled with 
anhydrous alcohol, and storing at low temperature. According to the method, the DNA sample in the karst cave 
water environment can be collected on site, the problems of 
DNA degradation, cross 
contamination and the like when a water sample is remotely transported to a laboratory for vacuum 
filtration are solved, and the collection method is low in cost, simple and convenient to operate and high in accuracy of the collected sample.