According to indoor free infiltration of muddy water film hole irrigation test data and free infiltration of clean water film hole irrigation as contrast, the free infiltration characteristics of muddy water film hole irrigation with different film hole diameters were investigated, the relationships between muddy water film hole irrigation infiltration and vertical one-dimensional muddy water infiltration was studied, the relationships between free infiltration of muddy water film hole infiltration parameters, wetting front movement parameters and different film hole diameters were established, and the cumulative infiltration volume model per unit film hole area of free infiltration of muddy water film hole irrigation with different film hole diameters, side infiltration volume model per unit film hole area, steady infiltration rate and wetting front movement model were put forward. The results showed that with the increase of film hole diameter of free infiltration for muddy water, the cumulative infiltration volume of single point of film hole was increased gradually, cumulative infiltration volume per unit film hole area and side infiltration volume per unit film hole area were decreased, the fitting parameters of K and α for cumulative infiltration volume per unit film hole area were decreased, and K c of side infiltration volume per unit film hole area was decreased, while α c was increased. Within the same infiltration time, vertical and horizontal wetting front movement distances were gradually increased with the increase of film hole diameter.