Mining method and system for improving straight-flat SAGD (Steam Assisted Gravity Drainage) utilization of interlayer developed oil reservoir

The invention discloses a mining method and system for improving straight-flat SAGD (Steam Assisted Gravity Drainage) utilization of an interlayer developed oil reservoir. The mining method comprises the following steps: determining geological master control influence factors influencing rising of a steam cavity; constructing a well pattern based on the geological master control influence factors; fracturing the interlayer based on the well pattern; breaking through the interlayer based on the well pattern; according to the thickness of the upper oil layer of the interlayer after breakthrough, steam huff and puff of the fishbone well are conducted, and then SAGD steam injection is conducted. Geological master control influence factors of the interlayer influencing the rising of the SAGD steam cavity are researched and determined, a well pattern form of vertical well steam injection, fishbone well auxiliary steam injection and lower horizontal well production is established, high-pressure steam injection is ad