The precutting technology for tunnel construction is widely used in foreign countries, but it is seldom used in China. The first archtype precutting machine is developed for loess geology, and the construction test is carried out in the loess tunnel. The key construction technologies, i.e. equipment positioning, partition cutting and jet grouting, equipment walking and construction organization, are presented by construction test; and the improvement and optimization measures are put forward. The test results show that the working state of the cutting system and the cutting and jet grouting function of the equipment can meet the design and construction test requirements; and the data support and research direction can be provided for the integrated research of synchronous cutting and jet grouting of the precutting technology. 