The pathway throttle and local throttle loss of oil flow in telescopic shock absorber were analyzed, and the pathway loss coefficient and equivalent length of piston holes were studied. According to the thickness and the pre-deformation of throttle slice, and the throttle holes area, the velocity points of valve opening were researched and the analytic formulas of shock absorber velocity when valve opening were given. With the velocity points of valve opening, the model of shock absorber outer characteristic was established by piecewise linear math function. Based on this, the CAE software for shock absorber outer characteristic was developed. A practical example of simulation of shock absorber outer characteristic was given with this CAE software, and the performance test was conducted to verify the CAE software. The results show that the CAE software is reliable, and the values simulated is close to that tested.