Abstract: The disc filter is one of the key components of micro-irrigation systems and plays an important role in filtering impurities and reducing clogging of emitters. However, the disc filter has a single type of discs and a narrow range of sand grain sizes for filtration, making it unable to meet the filtration requirements of different impurity particle sizes. Based on this, this research proposes a disc filter with adjustable filter mesh size by reasonably changing the tightness between discs, The disc filter can not only meet the filtration requirements of different impurity particle size ranges, but also help to reduce the manufacturing cost and operating cost. In order to test the hydraulic performance of disc filters with different mesh, five flow rates of 10, 15, 20, 25 and 30 m³/h were designed to test the change of head loss in clear water conditions with different mesh sizes of disc filters. In addition, three grades of small, medium and large sandy water with less than 75, 75～150 and 150～300 μm sand particles and three sand contents of 0.8, 1.0 and 1.2 g/L were selected to test the head loss and sand interception of disc filters with different mesh numbers under different grades and contents. The results show that: 1) Different mesh filtration objectives can be obtained by adjusting the disc tightness. Three types of discs can obtain 7 levels of tightness under three motor pressures, corresponding to filter mesh sizes of 50, 60, 75, 100, 120, 150, and 200. 2) There were differences in the head loss dynamics and sand interception of the 7 mesh disc filters. For small graded sandy water, the 200 mesh disc piece had the largest peak head loss, and the maximum values were all stabilized at about 16 m. The sand interception of the 200 mesh disc was 54, 73 and 84 g, which were significantly larger than that of other discs (P<0.05). For intermediate graded sandy water, the head loss was greater for 120, 150 and 200 mesh discs, with maximum values exceeding 6 m. The sand interceptions for 120 and 150 mesh discs were 72, 92 and 103 g, and 81, 92 and 95 g, respectively, which were significantly greater than that of the other discs (P<0.05). For large grades of sandy water, the 50, 60, 75, and 100 mesh discs all had greater sand interceptions and increased head loss. 3) Based on the TOPSIS method, the optimization configuration of the filter mesh size can be achieved. For small graded sandy water, a 200-mesh disc should be chosen. For intermediate graded sandy water, a 120-mesh disc should be chosen when the content is high, and a 150-mesh disc should be chosen when the content is low. For large grades of sandy water, a 50-mesh or 60-mesh disc should be selected when the content is high, and a 75-mesh or 100-mesh disc should be chosen when the concentration is low. This research effectively avoids the hidden danger of head loss surge while ensuring the best filtration effect, which can provide reference for the rational selection and use of disc filters under different sand content conditions in micro-irrigation systems to reduce filter head loss.