Mudstone has unfavorable engineering characteristics such as water absorption expansion softening, water loss shrinkage, dry cracking and easy disintegration, which often induces engineering diseases such as subgrade arching, slope collapse, canal dam and building cracking. In order to eliminate the bad characteristics of mudstone, F1 ionic soil stabilizer was used to improve mudstone. The no-load expansion test, triaxial unconsolidated undrained test, freeze-thaw cycle test, nuclear magnetic resonance test and XRD diffraction test were carried out on the solidified mudstone samples with different F1 content. And the physical and mechanical properties, micro pore structure and mineral composition of F1 reinforced mudstone were studied. The results show that F1 ionic soil stabilizer significantly improved the water sensitivity, compaction characteristics of mudstone soil and reduced the permeability and expansibility through ion exchange and hydrophobic action of sulfonated oil; After adding 0.5 L / m3 (the best content) of F1 ionic soil stabilizer into mudstone, the failure stress was increased by 1.97 times, the friction angle and cohesion were increased by 1.29 times and 1.64 times. What’s more, the frequency of freeze-thaw cycles had little effect on the cohesion and friction angle of F1 improved mudstone sample. The results of nuclear magnetic resonance test and XRD diffraction test show that there was no new material in mudstone before and after adding F1 ionic soil stabilizer. After adding F1 ionic soil stabilizer, the number of large, medium and small pores in the mudstone soil samples were decreased, the total pore volume was decreased, and the compactness of soil mass was increased.