Abstract: In order to explore the regulation mechanism of the parameters of Lee-Tarver trinomial ignition growth model,the effects of the parameters of Lee-Tarver trinomial ignition growth model on the impact initiation characteristics were analyzed and predicted based on the trinomial reaction rate equation.A finite element model of a small separator test with HMX as the donor explosive and H6JJ1 as the recipient explosive was established,and the critical thickness interval of the small separator was determined to be 1.2–1.3 mm when the model was successfully detonated.By adjusting the parameters of the trinomial ignition growth model of the main explosive,the variation of the critical thickness interval of the small separator was obtained when the model was successfully detonated,the influence of the coefficients of the Lee-Tarver trinomial ignition growth model on the impact initiation characteristics was clarified.Where b and c represent inward spherical particle combustion,and the value is 0.667;a,d,e,g andλ_{G2 min} are positively correlated with the pressure required for impact initiation.I,x,G₁,G₂，λ_igmax，λ_{G1 max} are negatively correlated with the pressure required for impact initiation.y and z are the pressure index,when 0＜p＜1,the pressure required for impact initiation is negatively correlated,and when p≥1,the pressure required for impact initiation is positively correlated.The regulation mechanism of the parameters of the trinomial ignition growth model is revealed.