In view of the high temperature of gas well in the northwest part of Gaoshi 19 well area and the unsatisfactory acidification effect caused by the high temperature and viscosity reduction of conventional self-steering acid，the self-steering acid was prepared by erucamide hydroxysulfonate amphoteric surfactant viscoelastic steering agent，corrosion inhibitor with high temperature resistance，cationic oligomer temperature inhibitor，etc. The temperature resistance，corrosion inhibition，retarding performance and self-steering performance of self-steering acid were evaluated，and then it was applied in Tiandong 110 well. The results showed that the suitable formula for self-steering acid was obtained as follows：20% HCl，8% steering agent EP-306B，2% iron ion stabilizer TYL，2% acid corrosion inhibitor GSY，1% acid corrosion inhibitor ZXJ，1% cationic oligomer DJW，6% organic acid YJS. The self-steering acid had good temperature resistance and corrosion inhibition performance. The maximum viscosity that reacted with cuttings at 150℃ was 48 mPa·s，and the corrosion rate of steel sheet was 49.8 g/（m2·h）. The retarding performance of self-steering acid was good，and the mass fraction of the acid only reduced by 3% after reacting with the cuttings for 40 minutes. The acidification of two cores with a permeability multiple of 21.4 in Gao 110 Well had a conversion rate of 72.2% for the low permeability core，indicating good self-steer performance. In the self-steering acid acidification of Tiandong 110 well，the predetermined acidification effect was achieved，and the flowback rate of residual acid reached 70%，realizing effective and uniform reservoir reformation. The self-steering acid system had a good acidification effect in heterogeneous layer of high temperature gas well.