The invention relates to the technical field of geothermal 
resource development and utilization, and discloses a simplified calculation method of a sleeve type 
ground heat exchanger, which comprises the following steps: 1) the thermophysical properties of a backfill material and surrounding rock soil are uniform and consistent, the thermophysical parameters of the backfill material and surrounding rock soil do not change along with the change of radial and vertical sizes, and the influence of 
groundwater seepage and soil 
moisture transfer is neglected; and 2) no heat conduction phenomenon exists in the vertical direction, that is, the 
heat transfer process is a two-dimensional 
heat transfer problem along the radial direction of the buried 
pipe. According to the simplified calculation method of the sleeve type buried 
pipe heat exchanger, by adopting the calculation method, grid division in the 
heat transfer calculation process of the sleeve type buried 
pipe heat exchanger can be reduced, and meanwhile, the complex three-dimensional unsteady-state 
heat transfer problem is simplified into the two-dimensional unsteady-state 
heat transfer problem; therefore, simplified calculation can be carried out on the sleeve type 
ground heat exchanger under different conditions, calculation efficiency is improved, and the method has certain 
actual use value and popularization value.