Abstract: Residual stress problem in fiber reinforced resin matrix composite structures is a key issue to restrict their large-scale applications in aerospace, automobile and architecture fields. Non-uniformity of temperature and curing degree fields during curing process of composites is an important factor in causing residual thermal stress and curing shrinkage stress. In view of investigating the sensitive degree of curing process temperature, thermal conductivity coefficient, convective heat transfer coefficient and thickness of structure to curing uniformity during curing process of fiber composite structures, the influence rule of the four key parameters on uniformity of temperature and curing degree fields was analyzed by numerical simulation. The simulation results show that the non-uniformity of the temperature field of composites increases and the non-uniformity of the curing degree field decreases when raising the curing process temperature; the non-uniformity of the temperature and curing degree fields both decrease when increasing convective heat transfer coefficient and thermal conductivity coefficient; the non-uniformity of the temperature and curing degree fields increase when increasing the thickness of composite structure. On these basis, the influence degree of the four key parameters on curing uniformity of composites was quantized by Morris global sensitivity analysis method. The sensitive degree order of curing uniformity corresponding to the four key parameters from high to low is as follows: thickness of structure, thermal conductivity coefficient, curing process temperature, convective heat transfer coefficient.