In order to verify the performance parameters of XD-40 drilling rig, demonstration application is carried out in combination with the geothermal well project in Dongli District of Tianjin. During the drilling process, the drilling depth reached 2258.83m at 311mm diameter exceeding the rated drilling capacity of the drilling rig, which has proved the main technical performance of the lifting system, rotary system, hydraulic system, AC frequency conversion control system, data and instrument parameter monitoring system, data storage system, drilling rig base and drilling tower; meanwhile the overall layout, control system program and practical design of the drilling rig have been optimized and improved. XD-40 drilling rig is featured of a high degree of mechanization, meeting the requirements of deep hole drilling, and its application may be extended to geothermal, shallow oil and gas exploration and other fields.