This paper concentrates on discussing the influences of the non-critical characteristic parameters on alarm curve threshold in the ground proximity warning system for airliner. The civil aircraft flight kinematics model is established based on its kinematic characteristics. Besides, according to the calculation of markov chain of discrete topographic height distribution, the two-dimensional terrain model is established. In addition, using simulation test statistics, this paper analyses the influence of pilot operation delay, terrain steep degree, plane normal overload and aircraft flight path angle, four parameters on alarm curve threshold based on the model. Finally, simulation of this warning system is performed in Matlab. The result shows the four parameters has effects on the slope and ranges of the alarm curve by not changing the alarm curve threshold.