The coupling effects of wax injection process parameters on the quality of wax patterns in investment casting were systematically investigated. Production experiments were conducted to analyse the influence of key parameters, including wax temperature (52~65 ℃), wrapping pressure (1.5~2.5 MPa), flow rate (80~200 cm3/s) and cycle time, on the formability, dimensional accuracy, and surface defects of wax patterns. The results show that when the wax temperature exceeds 60 ℃, the shrinkage rate increases, leading to depression, whereas temperatures below 55 ℃ result in insufficient filling capacity and mold sticking. The wrapping pressure requires dynamic adjustment to balance mold deformation and wax pattern density. The synergistic optimization of the flow rate and injection hole diameter reduces cold shuts and gas entrapment. By establishing a defect-parameter adjustment model, an optimization strategy of “prioritizing pressure and flow rate, followed by temperature fine-tuning” is proposed.