Abstract: In response to severe loading conditions of hillside tractor chassis, which result in insufficient strength and easy fracture of twisted shell, a finite simulation analysis model was established using Nastran and Hypermesh under three working conditions of bumps, slopes and steering, for verification and calculation．According to simulation analysis results, rationality of shell structure was judged, and strength safety factor was effectively improved by changing structural design of bending waist shell, and strength of bending waist shell was verified by special tests under three harsh conditions, weak parts of shell were physically tested by ultrasonic instruments, and shell has no damage．Test results showed that theoretical design and simulation of bending waist shell were reliable and feasible．