Abstract: Aiming at the existing “Guidelines for Design of Highway Safety Facilities” which is lack of risk analysis for highway guardrail in the corner, protection performance of the car guardrail system were studied in sharp sections, high speed, large angle of collision. The collision processes in collision angle equal 25 degree and with the velocity of car at 80km/h or 100km/h respectively were simulated by the means of finite element method (built model by Pro E, preprocessed by Hyper Mesh, simulated by LS DYNA). 4 indicators, vehicle′s tractory, acceleration, enery and damage,were putted forward to assess the effect of guardrail.meanwhile a new type of barrier with flexible buffer device was designed. The results indicate that the A level of w beam guardrail can′t meet the collision protection needs which that the intersection angle of it with column is less than 60 degree and maximum instantaneous deceleration of vehicle exceeds 20g in simulation. It indicate that the new device could utilize steel rope absorbers to buffer the collision processes. Compared with the traditional fence, maximum deformation of vehicle is only its 14% and the ratio of kinetic energy into internal energy fell by 40% yet. And it guides it return to its normal lane that prevents the following secondary accidents.