Abstract: In order to further understand the practical effect and value of the lime nail composite anchor, a new type of support structure, the in-situ test was conducted. Based on the analysis of the test results, the rule of mechanical and thermal variation in the soil around lime nails and the evaluation of the bearing capacity of the new structure are carried out. The test results show that:(1)The setting of lime nails has a significant effect on the temperature, expansion pressure and pore water pressure of the surrounding soil. Within the reasonable spacing range of lime nails, the smaller the spacing of lime nails, the more significant the effect on the expansion pressure, temperature and pore water pressure of the soil, and the greater the consolidation rate of the soil; (2)Compared with ordinary bolts, the uplift bearing capacity of lime nail composite bolts has been significantly improved. Within the reasonable spacing range of lime nails, the smaller the spacing of lime nails, the greater the uplift bearing capacity of lime nail composite bolts. Based on the collected measured data, the influence of the temperature increment, expansion pressure and horizontal depth of the soil around the lime nail on the pore water pressure is analyzed by multiple regression, and a reasonable regression model is obtained. The analysis results show that the expansion pressure, temperature increment and horizontal depth of the soil around the lime nail have a significant influence on the pore water pressure of the soil, the expansion pressure and temperature increment not only have linear influence on the pore water pressure, but also have non-linear influence and cross influence, while the horizontal depth has only linear influence on the pore water pressure.