To address the problem that the conventional mechanical bridge plugs are difficult to set and hydraulic fracturing operations are constrained under casing deformation conditions in shale gas horizontal wells in the Luzhou area of southern Sichuan，this study aims to clarify the sealing pressure-bearing capacity and engineering applicability of liquid gel plugs in deformed casing. A liquid gel plug system composed of functionally modified polyacrylamide（TSRP）and polyethyleneimine （PEI）was investigated. Through rheological and gelation performance evaluation，combined with field-derived real deformed casing samples，a sealing pressure-bearing test platform was established. Systematic pressure-bearing experiments were conducted under different casing deformation types，deformation section lengths，filling degrees，and combinations of multiple deformation types，and a prediction model for sealing pressure-bearing capacity was developed. The results showed that before gelation，the liquid gel plug exhibited an apparent viscosity of 204 mPa·s under downhole shear conditions，demonstrating pronounced shear-thinning behavior and good pumpability. At 90 ℃，gelation began after 2—3 h and was completed within 3—4 h，with the final gel strength of grade I. Pressure-bearing tests indicated that in A-，B-，and C-type deformed casing sections，the maximum sealing pressure-bearing capacities of the liquid gel plug in deformation lengths of 1，3，and 5 m were 0.57—2.06 MPa，0.77—2.50 MPa，and 0.98—3.83 MPa，respectively，showing a significant increase with increasing sealing length and deformation severity. In C-type deformed casing，when the filling degree increased from 0.1 to 1.0，the sealing pressure-bearing capacity rose from 0.15 MPa to 2.54 MPa. Under a fixed total casing length，when the deformation section length was reduced from 3 m to 0.6 m，the sealing pressure-bearing capacity was increased from 2.54 MPa to 3.20 MPa. Among multiple deformation combinations，the A-type and C-type combination exhibited the highest sealing pressure-bearing capacity，reaching up to 4.31 MPa. Based on the experimental results of liquid gel plug sealing performance，a sealing pressure-bearing prediction model was established using grey relational analysis，providing guidance for field applications.