In order to improve the temperature and shear resistance of linear gel fracturing fluid，the composite linear fracturing fluid LG-2 was prepared by using organic boron/zirconium composite crosslinking agent（FHBZ-1），partially hydrolyzed polyacrylamide （HPAM） and polyhydroxy alcohol. The crosslinking performance，temperature and shear resistance and gel breaking performance of LG-2 linear gel fracturing fluid system were evaluated. The field application was carried out on a shale gas well in the West. The results showed that LG-2 linear gel fracturing fluid had better crosslinking performance，temperature and shear resistance than HPAM/organic zirconium single gel system. The final viscosity of LG-2 linear gel fracturing fluid was 103 mPa·s after constant shearing 120 min at 110 ℃ and 170 s^-1，while that of HPAM/ organic zirconium gel was 48 mPa·s. The peak viscosity of LG-2 linear gel fracturing fluid was 448 mPa·s after constant shearing at 130 ℃ and 170 s^-1 . LG-2 linear gel fracturing fluid had low viscosity and residue after gel breaking at 60 ℃ and 90 ℃. The field test results of shale gas well showed that LG-2 linear gel fracturing fluid system had excellent performance of fracture making and sand carrying.