Using the head loss and filtration efficiency of the micro-pressure filtration flushing tank as the assessment indicators, an orthogonal experimental design of four factors, including inlet flow rate, mineralization degree, sediment concentration and filter diameter, was carried out. The projection pursuit regression (PPR) method was used to analyze the weight of the four factors, and then 20 sets of experimental data were selected to establish a prediction model for the head loss and filtration efficiency of the micro-pressure filtration flushing tank under the condition of sandy and brackish water, by which the influence of sandy and brackish water on the head loss and filtration efficiency of the micro-pressure filtration flushing tank was explored. The research results indicate that the factors affecting the head loss of the micro-pressure filtration flushing tank ranked in descending order are as follows: inlet flow rate, sediment concentration, mineralization degree, and filter diameter; whereas those affecting filtration efficiency ranked in descending order are: sediment concentration, inflow rate, salinity, and filter diameter. In addition, the PPR model can produce an overall qualification rate of 100% for prediction accuracy. According to the prediction results, when the inlet flow rate is 6-7 m3/h, the sediment concentration is 0.5-1.0 g/L, the mineralization degree is 0-2.0 g/L, and the filter diameter is 0.125-0.180 mm, there is a minimum value of head loss; when the inlet flow rate is 9-10 m3/h, the sediment concentration is 1.75-2.00 g/L, the mineralization degree is 0-3.0 g/L, and the filter diameter is 0.125-0.150 mm, there is a maximum value of filtration efficiency. The experimental results of the physical model can provide a technical basis for the practical application of micro-pressure filtration flushing tanks.